SF 


UC-NRLF 


I 


33 


THE  HERITANCEOFTHE 

SIZE,  SHAPE  AND  COLOR  OF  HENS'  EGGS 


A  THESIS 


PRESENTED    ': 


THE    DI:< 

DOCTOR  OF  PHILOSOPHY 


BY 

EARL  WHITNEY  BENJAMIN 
1914,  1920 


EXCHANGE 


A  STUDY  OF  SELECTIONS  FOR 

THE  VARIATION  AND  INHERITANCE  OF  THE 

SIZE,  SHAPE  AND  COLOR  OF  HENS'  EGGS 


A  THESIS 


PRESENTED    TO   THE    FACULTY  OF   THE    GRADUATE  SCHOOL    OF 
CORNELL  UNIVERSITY 


FOR    THE    DEGREE    OF 

DOCTOR  OF  PHILOSOPHY 


BY 

EARL  WHITNEY,  BENJAMIN 
1914,  1326^ 


•  V  :  :•"'•  :..: 

•:!L!  ; 


EXCHANGE 


CONTENTS 

PAGE 

Review  of  literature 195 

Methods  of  investigation 198 

Size  character 199 

Shape  character 

Photographing  the  eggs  for  size  and  shape  studies 202 

Color  character 201 

Methods  common  to  studies  of  all  the  characters 206 

Results : 208 

Inheritance  studies 208 

Variability  of  production  due  to  differences  between  the  parent  types 208 

Inheritance  of  mean  egg  type 215 

Relation  of  egg  incubated  to  mean  egg  type  of  bird  hatched 227 

Relation  of  eggs  incubated  to  types  of  eggs  produced  by  the  respective  birds 

hatched 244 

Miscellaneous  studies 250 

Relationship  of  size  and  shape  of  eggs '. 250 

Incubation  effects  of  egg  type 252 

Relative  variability  of  the  productions  of  successive  years 253 

Variations  in  types  of  eggs  produced  during  successive  months  and  years 254 

Size  character 255 

Shape  character 259 

Color  character 262 

Variations  hi  types  of  successive  individual  eggs 266 

Variations  in  types  of  eggs  produced  in  different  calendar  months 267 

Relation  between  vigor  of  the  chick  and  size  of  the  egg  from  which  it  was 

hatched 269 

Relation  between  male  and  female  weights  for  chicks  of  the  same  age 270 

Relation  between  size  of  the  chick  and  size  of  the  egg  from  which  it  was 

hatched 271 

Discussion  of  results 305 

Summary 307 

Acknowledgments 309 

Bibliography 310 


191 


478389 


A  STUDY  OF  SELECTIONS  FOR  THE  SIZE,  SHAPE,  AND  COLOR 

OF  HENS'  EGGS 


A  STUDY  OF  SELECTIONS  FOR  THE  SIZE,  SHAPE,  AND  COLOR 

OF  HENS'  EGGS1 

E!AKL  W.  BENJAMIN 

The  study  here  reported  was  conducted  from  the  spring  of  1911  until 
1919,  with  the  purpose  of  determining  the  results  that  may  be  obtained 
by  selecting  the  breeding  stock  of  the  domestic  fowl,  and  the  eggs  for 
hatching,  in  order  to  change  the  size,  shape,  and  color  of  the  eggs  pro- 
duced by  the  offspring.  There  is  a  certain  type  of  egg  which  especially 
meets  the  desires  of  the  respective  customers  in  various  markets.  It  is 
usually  not  practicable  to  grade  the  eggs  closely,  and  it  becomes  necessary 
to  select  and  develop  the  flocks  so  that  the  proportion  of  eggs  unsatis- 
factory to  the  customer  may  be  reduced  to  the  minimum. 

The  wholesale  trade  of  the  New  York  City  market  requires  the  size 
and  shape  of  the  eggs  to  be  such  that  the  eggs  are  not  crowded,  but  fit 
snugly,  in  the  fillers  of  the  commercial  thirty-dozen  cases;  this  means 
an  egg  about  2f  inches  long  and  If  inches  wide,  and  usually  weighing 
from  2  to  2|  ounces  when  fresh.  Shipping  only  the  eggs  of  proper  size 
and  shape  insures  less  breakage,  better  appearance,  and  a  resulting  higher 
sale  value.  The  New  York  City  market  has  a  special  demand  for  white- 
shell  eggs  and  will  sometimes  pay  from  eighteen  to  twenty  cents  a  dozen 
more  for  eggs  having  chalk-white  shells  than  for  those  varying  from  cream- 
tinted  to  brown. 

REVIEW  OF  LITERATURE 

The  study  of  the  external  characters  of  eggs  seems  to  date  from  a  com- 
paratively recent  period,  and  even  at  the  present  time  the  published 
data  with  respect  to  these  characters  are  very  meager. 

Tradition  tells  us  (in  Horace,  Lib.  II,  st.  4)  that  the  eggs  of  pullets 
are  longer  than  those  of  hens,  and  that  pullets'  eggs  produce  a  larger 
proportion  of  male  chicks  than  do  hens'  eggs.  This  tradition  has  been 
developed  until  many  persons  believe  that  long  eggs  produce  cockerels 
and  round  eggs  produce  pullets  when  incubated. 


1  This  study  completes  the  work  reported  in  part  in  a  thesis  presented  by  the  writer  to  Cornell  Uni- 
versity in  1912  for  the  degree  of  master  of  science  in  agriculture,  and  continued  in  a  thesis  presented  to 
Cornell  University  in  1914  in  partial  fulfillment  of  the  requirements  for  the  degree  of  doctor  of  philosophy. 

195 


196  EARL  W.  BENJAMIN 

The  size  and  shape  of  the  egg  is  shown  by  Curtis  (1911  a)2  and  by  Surface 
(1912)  to  be  due  partly  to  the  structure  of  the  oviduct,  which  may  probably 
be  considered  an  inherited  character  as  claimed  by  Newton  (1893-96). 
This  is  in  accordance  with  the  view  of  Thompson  (1908).  This  physical 
influence  on  the  size  and  shape  of  the  egg  described  by  Thompson  (1908) 
is  denied  by  Horwood  (1909),  but  without  convincing  evidence. 

The  shape  of  the  egg  seems  to  depend  on  its  size,  according  to  Curtis 
(1914  a).  The  same  author  shows  good  correlations  between  the  two 
dimensions  of  eggs,  and  between  either  of  these  dimensions  and  the  weight. 
This  agrees  with  the  conclusions  of  Pearl  and  Curtis  (1916). 

Curtis  (19 14  a)  claims  that  the  larger  eggs  are  due  to  a  greater  relative 
deposition  of  egg  white,  while  Atwood  (1914)  finds  indications  contrary 
to  this. 

The  size  of  the  egg  seems  to  be  affected  by  the  feed,  according  to 
Atwood  (1914),  and  the  same  author  shows  a  marked  seasonal  fluctuation 
in  the  weight'  of  eggs  laid,  the  weight  gradually  increasing  from  July 
to  February  and  decreasing  from  March  to  July.  This  agrees  with 
Curtis  (1914  a)  and  with  Fere  (1898  b),  who  claim  that  the  eggs  are 
smaller  at  both  the  beginning  and  the  end  of  the  litter.  Rice,  Nixon,  and 
Rogers  (1908)  and  Riddle  (1911)  show  a  striking  effect  of  the  amount  of 
food  consumed  on  the  number  of  eggs  produced.  According  to  these 
workers,  both  the  amount  of  food  consumed  and  the  number  of  eggs  pro- 
duced seem  to  be  variable  factors  agreeing  in  their  seasonal  fluctuations 
with  the  size  of  the  egg,  as  just  noted.  Curtis  (1914  a)  also  shows  a  grad- 
ual reduction  in  size  for  the  successive  eggs  in  the  clutch.  Hadley  (1919) 
shows  a  monthly  fluctuation  in  the  egg  weight  of  thirty-nine  White 
Plymouth  Rocks  which  corresponds  closely  with  the  monthly  numerical 
production.  He  finds  also  that  the  percentage  increase  in  egg  weight 
during  the  two  modal  months  of  increased  production  (April  and  Sep- 
tember) is  positively  indicative  of  the  relative  annual  numerical  produc- 
tion of  the  respective  birds. 

According  to  Curtis  (1914  a),  the  size  of  the  eggs  increases  as  the  bird 
matures.  Curtis  states  also  that  the  variations  among  the  eggs  produced 
by  individuals  were  not  so  great  as  the  variations  in  the  flock's  production, 
and  seemed  to  diminish  as  the  birds  matured.  This  agrees  with  the 

2  Dates  in  parenthesis  refer  to  Bibliography,  page  310. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   197 

results  obtained  in  a  study  of  the  number  of  leaves  to  a  whorl  in 
Ceratophyllum  made  by  Pearl,  Pepper,  and  Hagle,3  and  in  a  later  study 
for  egg  shape  made  by  Pearl  (1909).  Similar  variations  in  sparrows' 
eggs  have  been  observed  also  by  Pearson  (1902  b). 

Stewart  and  Atwood  (1909)  report  that  chicks  hatched  from  pullets' 
eggs  are  not  so  large  nor  so  vigorous  as  those  hatched  from  the  eggs  of 
hens  two  and  three  years  old.  Atwood  (1914)  mentions  this  fact  as 
showing  that  chicks  hatched  from  larger  eggs  are  larger  and  more  vigorous 
than  others.  It  would  seem  that  there  is  danger  here  of  attributing 
any  possible  defect  of  the  embryo  due  to  the  immaturity  of  the  parent, 
to  the  smaller  size  of  the  egg,  which  also  is  due  to  the  immaturity  of  the 
parent.  The  writer  does  not  see  proof  that  a  smaller  egg  produces  a 
smaller  and  weaker  chick  irrespective  of  the  maturity  and  condition  of 
the  parent. 

Pearl  and  Curtis  (1916)  found  that  the  two  characters  size  and  shape, 
as  measured  by  weight,  length,  and  breadth,  show  different  degrees 
of  variability,  ranging  from  the  most  variable  to  the  least  variable  in 
the  order  named.  Pearl  and  Curtis  were  able  also  to  strengthen  their 
previous  conclusions  that  the  index  and  the  weight  are  negatively  cor- 
related. They  found  that  dwarf  or  abnormal  eggs  do  not  occur  more 
frequently  at  the  beginning  or  at  the  end  of  the  litter  than  at  other  times. 
During  the  eight  years  previous  to  their  study,  5.15  per  cent  of  all  the 
birds  kept  at  the  Maine  experiment  station  produced  one  or  more  dwarf 
eggs,  and  only  3.5  per  cent  of  this  5.15  per  cent  produced  more  than  two 
dwarf  eggs. 

Abnormal  types  of  eggs  have  been  reported  also  by  Von  Nathusius 
(1895),  Fere  (1897  and  1898  b),  Herrick  (1899,  a  and  b),  Hargitt  (1899 
and  1912),  Parker  (1906),  Patterson  (1911),  Glaser  (1913),  Curtis  (1914b), 
Chidester  (1915),  and  Weimer  (1918).  Some  of  the  abnormalities  reported 
might,  of  course,  prove  to  be  inherited,  especially  such  as  the  double 
yolks  found  by  Glaser  (1913);  however,  since  this  publication  is  concerned 
with  nonnal  eggs,  further  discussion  of  rare  monstrosities  may  be  omitted. 

The  coloration  of  the  shells  of  eggs  has  long  been  a  subject  of  interest 
to  oologists.  According  to  Newton  (1893-96),  older  birds  usually  lay 
darker-shell  eggs.  Newton  says  that  some  of  the  color  is  applied  to  the 

3  Variation  and  differentiation  in  Ceratophyllum.    By  Raymond  Pearl,  Olive  M.  Pepper,  and  Florence  J. 
Hagle.     Carnegie  Inst.     Pub.  no.  58 : 1-136.     1907. 


198  EARL  W.  BENJAMIN 

shell  early  in  its  development,  while  some  is  added  later  —  as  is  indicated 
by  the  lighter  shade  of  an  egg  that  has  been  laid  prematurely,  due  to 
some  excitement.  The  intensifying  of  the  pigment  with  the  age  of  the 
bird  is  supposed  to  continue  until  she  has  attained  her  full  vigor,  when 
the  tint  begins  to  decline  gradually.  Newton  believes  that  except  for 
individual  differences  the  pigment  is  fairly  constant  in  supply. 

Sorby  (1875)  found  seven  substances  which  in  various  mixtures  are  sup- 
posed to  produce  all  eggshell  colors.  These  substances  were  oorhodeine, 
oocyan,  banded  oocyan,  yellow  ooxanthine,  rufous  ooxanthine,  a  substance 
giving  narrow  absorption-bands  in  the  red,  and  lichnoxan thine.  They  are 
said  to  be  closely  connected  with  either  haemoglobin  or  bile  pigments. 

M'Aldowie  (1886)  and  many  others  have  advanced  theories  as  to  the 
cause  of  variation  in  eggshell  color.  The  general  opinion  seems  to  be  that 
the  color  is  very  unstable  and  variations  do  occur  frequently,  and  that 
general  tints  or  colors  are  inherited.  Horwood  (1909)  gives  it  as  his 
opinion  that  coloration  of  the  shells  of  birds'  eggs  has  absolutely  no 
connection  with  mendelian  principles. 

According  to  Surface  (1912),  the  color  of  eggshells  is  probably  added 
from  glands  in  the  vagina  or  adjoining  parts  of  the  oviduct,  and  it  may 
reasonably  be  supposed  that  a  function  of  this  nature  would  be  inherited. 
Such  a  supposition  agrees  with  the  results  of  Benjamin  (1912  and  1914), 
which  are  discussed  later  in  this  report. 

All  these  studies,  made  by  various  workers,  show  conclusively  that 
with  respect  to  many  characters,  including  size,  shape,  and  color,  there 
is  a  characteristic  type  of  egg  to  be  accredited  to  each  individual,  and 
that  some  degree  of  inheritance  has  been  found  to  exist. 

METHODS  OF  INVESTIGATION 

The  investigation  described  in  this  memoir  was  begun,  in  the  spring 
of  1911,  by  selecting  fifty  eggs  for  hatching  for  each  of  the  follow- 
ing nine  characters  —  three  characters  being  grouped  in  each  of  three 
selection  studies: 

Size  selections  Shape  selections  Color  selections 

Large  Long  Chalk-white 

Medium  Normal  Cream-tinted 

Small  Round  Brown-tinted 


STUDY  OF  SELECTIONS  FOB  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   199 

The  eggs  were  selected  from  three-year-old  Single  Comb  White  Leghorn 
hens,  and  an  effort  was  made  to  get  eggs  from  hens  that  consistently  laid 
the  type  of  egg  selected.  The  Single  Comb  White  Leghorn  breed  was 
used  for  the  study  because,  first,  it  is  the  commonest  breed  in  New  York 
State,  and  secondly,  because  it  was  desired  to  study  these  commercial 
characters  of  eggs  by  the  use  of  commercial  breeds,  and  the  Leghorn 
predominates  on  commercial  egg  farms  in  the  United  States.  The  birds 
used  were  from  the  high-producing  trap-nested  stock  of  the  well-established 
Cornell  strain. 

SIZE    CHARACTER 

The  basis  for  selecting  eggs  for  the  size  character  was  weight.  A  Harvard 
balance,  equipped  with  a  slide  reading  to  10  grams  in  tenths,  was  used 
early  in  the  work,  but  this  was  later  replaced  by  a  special  direct-reading 
balance  (fig.  7).4  Exact  weights  were  used  at  first,  but  later  the  weights 
were  recorded  in  2-gram  classes  and  could  be  transferred  directly  for 
use  in  the  correlation  tables.  Eggs  weighing  more  than  50  grams  and 
not  more  than  52  grams  were  recorded  as  51  grams  in  weight  and  were 
grouped  in  the  50-52-gram  class  in  the  correlation  tables. 

The  eggs  were  weighed  as  soon  as  possible  after  they  were  laid,  in 
order  to  avoid  any  serious  losses  due  to  evaporation.  When  it  was  neces- 
sary to  hold  them  for  some  time  before  weighing,  they  were  kept  packed 
and  in  a  cool,  rather  moist,  place.  After  January,  1913,  the  eggs  were 
held  in  an  artificially  cooled  room  at  a  temperature  of  from  32°  to  40°  F. 

The  eggs  selected  for  incubation  each  year  were  weighed,  as  well  as 
all  the  eggs  produced  by  any  of  the  hens  in  the  size-character  studies. 
In  the  early  part  of  the  work  the  eggs  selected  for  incubation  were  also 
measured  and  their  length  and  breadth  recorded. 

Just  before  hatching,  the  eggs  were  placed  in  pedigree  trays.  The 
trays  used  in  1911  were  so  constructed  that  it  seemed  advisable  to  put 
into  one  compartment  all  the  eggs  produced  by  the  same  hen.  If  more 
than  one  egg  in  a  compartment  hatched,  it  was  necessary  to  use  the  average 
of  all  the  hatched  eggs  in  that  compartment,  in  order  to  calculate  the 
average  type  of  egg  which  hatched.  This  gave  a  fairly  accurate  result 
because,  as  a  rule,  all  the  eggs  laid  by  the  same  hen  are  of  the  same  general 
type.  However,  as  this  method  allowed  the  possibility  of  some  error, 

4  This  balance  was  imported  by  Cornelius  Kahlen,  New  York  City. 


200 


EARL  W.  BENJAMIN 


FlG.   7.      SPECIALLY    DESIGNED    DIRECT-READING    BALANCE    FOR    WEIGHING    EGGS    AND 

CHICKS 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  201 

all  incubated  eggs  were  individually  pedigreed  after  1911.  For  the  1912 
and  1913  hatches,  the  compartments  of  the  pedigree  trays  were  made 
small  enough  to  hold  just  one  egg,  and  thus  it  was  possible  to  know  from 
which  egg  each  chick  hatched.  In  the  1914  hatch  and  after  that  time, 
the  chicks  were  satisfactorily  hatched  in  cloth  bags. 

The  day-old  chicks  were  weighed  on  the  same  direct-reading  egg  scales 
as  were  used  for  the  eggs.  After  this  first  weighing  the  chicks  were 
individually  weighed  every  four  weeks  on  a  special  type  of  milk  balance, 
by  which  the  weights  could  be  accurately  estimated  to  1/100  pound. 
When  these  weights  were  transformed  to  grams,  as  was  done  for  some 
of  the  correlation  tables,  the  calculation  was  made  by  means  of  the  formula, 
1  pound  =  453.6  grams.  In  the  early  part  of  the  work  a  separate  record 
was  made  of  the  vigor  of  the  chicks. 

SHAPE  CHARACTER 

The  basis  for  selecting  eggs  for  shape  was  the  index  figure  obtained 
by  dividing  the  greatest  width  of  the  egg  by  its  greatest  length  and 


FlG.    8.      SPECIALLY  DESIGNED  RATCHET  MICROMETERS  HELD 
BY  WOODWORKING  CLAMP,  FOR  EGG  MEASUREMENTS 

multiplying  the  result  by  100.  The  measurements  were  made  by  specially 
constructed  ratchet  micrometers  with  a  J-inch  face  (fig.  8).5  One 
micrometer  was  adjusted  for  the  egg  length  and  one  for  the  egg  width. 

5  These  were  manufactured  by  Brown  &  Sharpe,  Providence,  Rhode  Island. 


202 


EARL  W.  BENJAMIN 


FlG.  9.  LIGHT,  AND  FRAME  FOR  HOLDING 
EGGS,  AS  USED  FOR  THE  SHADOW  PHOTO- 
GRAPHIC PROCESS 

The  wire  circle  around  the  light  was  used  early  in 
the  work  to  hold  a  curtain  for  preventing  reflection 
of  light  from  the  sidewalk.  The  eggs  are  shown  as 
they  are  placed  on  the  film  ready  for  exposure. 
At  the  right  is  shown  the  frame  used  for  arranging 
the  eggs  in  their  proper  positions 


The  micrometers  were  held  in  a  wood- 
working clamp  to  prevent  error  due 
to  expansion  which  might  result  if 
they  were  warmed  by  being  held  in 
the  hand  of  the  operator. 

All  eggs  incubated  for  the  shape- 
character  studies,  or  produced  by  hens 
in  the  shape-selection  studies,  were 
measured  and  the  data  recorded. 

PHOTOGRAPHING   THE    EGGS 
FOR   SIZE   AND   SHAPE   STUDIES 

It  was  thought  desirable  to  have 
some  sort  of  graphic  representations 
of  the  eggs  selected  for  size  and  shape, 
and  to  compare  these  with  represen- 
tations of  the  eggs  that  the  pullets 
produced  during  the  following  year. 
Photography  was  the  first  method  of 
representation  considered.  Since  this 
was  very  expensive,  however,  the 
practice  of  allowing  the  shadows  of 
the  eggs  to  fall  directly  on  sensitized 
photographic  paper  was  adopted.6 
A  sheet  of  sensitized  paper,  9  by  11 
inches  in  size,  is  slipped  into  the 
back  of  a  specially  constructed  frame, 
where  it  is  held  securely  by  a  wooden 
support.  The  sensitized  paper  is 
slipped  in  back  of  a  sheet  of  stock 
film  glued  in  the  frame;  this  film,  if 
kept  clean,  does  not  hinder  the  re- 
production, .reflects  much  of  the  dif- 
fused light,  and  thus  prevents  the 
blurring  of  the  shadow.7 

The  eggs  are  placed  on  the  film  as 
shown  in  figure  9,  and  are  held  in 

6  It  was  necessary  to  use  high-contrast  paper  for  this 
work,  in  order  to  obtain  distinct  black  and  white  tones. 

7  This  stock  film  is  the  base  used  for  photographic 
films  before  the  gelatinous  coating  is  applied.     It  is 
transparent. 


STUDY  OF  SELECTIONS  FOB  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   203 


FlG.    10.      PHOTOGRAPHIC   STUDY  OF    SIZE   AND    SHAPE    CHARACTERS 

This  shows  the  appearance  of  the  sensitized  paper  after  exposure  under  the  eggs  and  subsequent 
development.  A  record  is  made  at  the  time  of  the  exposure,  identifying  each  egg  so  that,  if  desired, 
it  may  be  used  later  in  a  group  with  all  other  eggs  laid  by  the  same  hen 


204  EARL  W.  BENJAMIN 

place  by  small  circles  of  stock  film  made  by  cutting  strips  of  film  about 
3  inches  long  and  J  inch  wide  and  gluing  the  ends  together.  These  film 
circles  are  transparent,  thus  casting  no  shadow,  and  are  therefore  much 
more  suitable  than  if  made  of  an  opaque  substance  such  as  cardboard  or 
metal.  When  the  twelve  eggs  that  are  to  be  reproduced  on  each  9x  11- 
inch  sheet  are  placed  on  the  film,  they  are  arranged  evenly  by  means 
of  a  separate  frame  shown  in  figure  9,  which  divides  the  9x1 1-inch 
space  into  twelve  equal  parts.  This  frame  is  removed  before  the  repro- 
duction is  made.  After  the  frame  with  the  eggs  on  it  is  in  place  under 
the  light,  the  light  is  turned  on  for  an  exposure  varying  with  its  power 
and  its  distance  from  the  eggs.  In  this  study,  a  200-candle-power  tungsten 
light,  with  a  special  parallel-ray  reflector,  was  used,  about  9  feet  distant 
from  the  eggs,  and  an  exposure  of  just  one  minute  was  required.  A  red 
light  was  used  when  working  with  the  sensitized  paper. 

After  the  exposed  sheet  has  been  developed,  the  eggs  appear  as  white 
outlines  on  a  black  background  (fig.  10).  A  key  is  arranged  at  the 
time  when  the  exposure  is  made,  whereby  the  numbers  of  the  eggs  repro- 
duced are  known,  so  that  certain  eggs  can  be  cut  out  of  the  plate  at  any 
time,  rearranged,  and  photographed. 

COLOR    CHARACTER 

The  method  of  making  selections  for  the  color  character,  and  of  recording 
the  colors  for  reference  during  succeeding  generations  of  the  birds,,  was 
a  difficult  one  to  develop.  Various  schemes  were  contemplated  and 
many  of  these  were  tried.  Schemes  of  using  color  tops  or  wheels,  various 
types  of  colorimeters,  colored  photography,  and  so  forth,  were  considered, 
but  were  discarded  as  being  too  slow,  expensive,  or  inaccurate.  It  is  very 
difficult  to  match  the  color  of  an  egg  with  that  of  any  other  surface.  It  was 
decided  that  if  a  system  of  matching  colors  was  to  be  followed,  in  order 
to  do  the  work  rapidly  the  eggs  must  be  matched  to  other  eggs  of  standard 
colors.  s 

By  a  careful  inspection  of  all  eggs  produced  on  the  plant  for  several 
cfcays,  a  graduated  set  of  colors  containing  about  fifty  tones  from  chalk- 
white  to  dark  chocolate  brown  was  obtained.  The  first  seventeen  of 
these  tones  were  the  only  ones  used  in  the  experiment.  The  contents  of 
these  eggs  were  blown,  and  the  shells  were  numbered  consecutively  and 


MEMOIR  31 


PLATE  VII 


PLATE  VII 

KEY    TO    COLOR    NOTATION    USED     FOR    COLOR    STUDIES    OF    EGGS 


Color  notation  number 

Equivalent  in 
Repertoire  de  Coideurs 

Plate 

Ton 
(Tone) 

1. 

..1 
11 

..1 
......1 
2 
3 
....1 
1 
2 
3 
4 
1 

2 

3 

11 

4 

....11 
2 
10 
10 

5 

6 

7  

8  
9     .                    

9 
9 

10  
11       

.  .  .  .312 
....312 
67 
..36 
.....68 
68 

2 
1 
1 

12  
13  ;  

14  

..1 

2 
3 

4 

15 

16 

68 

17      

68 

206  EARL  W.  BENJAMIN 

arranged  in  a  tray.  These  standard  eggs  were  then  carefully  matched 
with  their  respective  colors  in  Repertoire  de  Couleurs*  (Plate  VII). 

The  color  of  eggshells  is  not  permanent  and  will  fade  considerably 
if  exposed  to  the  light  for  any  great  length  of  time.  The  practice  was 
tried  of  coating  the  shells  with  various  preparations  intended  to  preserve 
their  color,  but  this  was  not  successful,  as  all  these  preparations  contained 
so  much  color  in  themselves  that  the  color  of  the  shells  thus  coated  was 
materially  changed.  The  method  finally  followed  was  to  use,  as  standards, 
eggs  with  the  natural  surface.  The  tray  of  eggs  was  kept  covered  with 
a  black  cloth  except  when  in  use,  and  the  standard  eggs  were  replaced 
with  others  of  identical  color  at  intervals  varying  with  the  length  of  time 
they  were  used. 

A  clear  north  light  is  necessary  for  accurate  color  selection,  and  one 
must  have  a  trained  eye  in  order  to  be  sure  of  recording  the  correct  color. 
The  terms  chalk-white,  cream-tinted,  and  brown-tinted  are  used  merely 
to  designate  the  three  groups  of  colors,  in  order  to  show  the  type  of  eggs 
selected  for  each  lot.  The  color  recording  was  done  by  one  person  early 
in  the  experiment  and  by  another  person  later.  A  trial  was  made  of 
color  recording  by  several  inexperienced  persons  on  the  same  set  of  eggs 
for  several  succeeding  days,  and  the  percentage  of  error  was  found  to  be 
very  slight.  The  same  standard  scale  of  colors  was  used  thruout  the 
work.  The  colors  were  numbered  as  shown  in  Plate  VII,  and  these  num- 
bers were  used  in  the  correlations  and  other  calculations. 

METHODS  COMMON  TO  STUDIES  OF  ALL  THE  CHARACTERS 

The  chicks  used  in  this  study  were  reared  by  standard  methods,  in 
colony  houses  with  the  other  experimental  chicks  on  the  Cornell  experi- 
mental farm.  Previous  to  1913  the  mature  birds  were  kept  in  a  narrow 
house  divided  into  nine  pens,  one  pen  for  each  of  the  nine  characters. 
Under  these  conditions  the  one  selected  male  bird  for  each  pen  was  allowed 
freedom  in  the  pen.  During  the  1913  breeding  season  and  after,  individual 
mating  coops  were  installed,  and  individual  mating  was  followed  for  the 
remainder  of  the  experiment.  New  houses  were  used  for  the  stock  after 
1913  (fig.  11).  All  feeding,  trap-nesting,  and  other  details  of  management 

8  Repertoire  de  couleurs.  Published  by  La  Socie'te  Frangaise  des  Chrysanthe'mistes  and  Ren6  Oberthur, 
with  the  collaboration  of  Henri  Dauthenay  and  others.  1905. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  207 

were  conducted  under  the  supervision  of  the  manager  of  the  Cornell 
poultry  farm  and  in  accordance  with  the  usual  practice  on  that  farm. 
The  general  plan  was  to  save  all  the  chicks  until  maturity  and  then 
save  as  many  typical  specimens  from  each  group  as  could  be  satis- 
factorily housed.  Usually  about  120  females  and  30  males  were  kept 
for  the  study  of  the  three  characters,  size,  shape,  and  color.  When  the 
surplus  stock  was  culled  each  fall,  an  effort  was  made  to  save  the  birds 


FlG.    11.      TYPE   OF   HOUSE   USED   FOR   STOCK   AFTER    1913 

representing  the  extremes  of  the  types.  If  there  were  birds  that  had 
produced  no  chicks  during  the  previous  breeding  season,  these  birds  were 
usually  culled.  In  cases  in  which  nearly  all  the  members  of  a  certain 
family  had  developed  only  a  medium  quality  for  the  character  studied, 
the  whole  family  was  often  culled  to  make  room  for  more  promising  birds. 
A  large  proportion  of  cockerels  and  pullets  were  usually  saved  for 
the  first  year,  and  these  were  culled  fairly  closely  before  being  used  as 
breeders  during  the  succeeding  years. 


208  EARL  W.  BENJAMIN 

These  methods  of  selection  explain  why  so  few  records  are  actually 
available  for  the  study  of  some  of  the  characters. 

In  following  the  method  of  individual  mating,  each  male  to  be  mated 
with  any  females  in  the  pen  is  retained  in  a  coop.  Whenever  a  female 
is  removed  from  the  trap  nest,  the  attendant  finds  her  band  number 
on  a  posted  list  and  learns  the  band  number  of  the  male  with  which  she 
is  to  be  mated.  Before  placing  her  in  the  mating  coop,  however,  the 
work  is  further  checked  by  looking  for  the  hen  number  on  a  tag  attached 
to  the  coop,  and  also  by  comparing  the  color  of  her  band  with  the  color 
of  the  male's  band.  The  female  is  then  placed  in  the  coop  and  removed 
at  the  time  of  the  next  inspection  of  the  trap  nests.  Usually  about  twelve 
mating  coops  were  needed  in  each  house. 

Every  egg  laid  by  the  mature  birds  is  recorded  as  to  either  its  size, 
its  shape,  or  its  color,  in  the  same  way  as  the  original  incubated  eggs 
were  recorded.  This  enables  the  investigator  to  compare  the  character 
of  the  egg  incubated  with  the  eggs  which  the  resulting  pullet  produces. 
Many  of  the  eggs  from  hens  in  the  size  and  shape  selections  were  also 
photographed,  as  previously  explained. 

RESULTS 

The  results  of  the  investigation  may  properly  be  grouped  into  those 
concerned  with  the  inheritance  studies  and  those  concerned  with  other 
related  studies,  the  former  being  dealt  with  first. 

INHERITANCE    STUDIES 

Variability  of  production  due  to  differences  between  the  parent  types 

An  effort  was  made  to  determine  to  what  extent  the  variability  of  a  bird's 
production  was  dependent  on  the  differences  existing,  for  the  particular 
character,  in  the  respective  dam  and  sire.  The  studies  made  in  this  regard 
are  illustrated  in  tables  1  to  12,  and  a  summary  is  given  in  table  13.  In 
constructing  these  tables,  the  standard  deviations  for  each  of  the  three 
egg  characters  considered,  for  each  respective  year's  production,  were  calcu- 
lated, and  these  were  correlated  with  the  differences  existing  between  the 
means  of  the  respective  egg  character  for  all  the  eggs  produced  during  the 
life  of  the  respective  dam,  and  as  calculated  for  the  respective  sire.9 

9  The  life  mean  for  the  sire  was  obtained  by  averaging  his  respective  dam  and  sire.  The  character  of 
the  egg  from  which  the  first  sires  used  in  the  study  were  hatched,  was  taken  as  the  mean  for  these  first  sires. 

When  a  class  is  designated  by  one  figure,  that  figure  represents  the  upper  limit  of  the  class;  when  a  class 
is  designated  by  two  figures,  the  upper  figure  is  included  in  the  class. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  209 

It  is  clear  that  no  correlation  exists  for  these  characters.  This  state- 
ment, of  course,  has  reference  to  the  first  generation  only.  This  result 
does  not  show  that  when  comparing  the  mean  characters  for  the  several 
offspring  from  a  certain  mating,  one  may  not  find  a  variability  depending 
on  the  difference  between  the  same  characters  for  the  respective  dam 
and  sire. 


TABLE  1.  STANDARD  DEVIATION  OF  EGG  SIZE  (WEIGHT  IN  GRAMS)  DURING  FIRST  YEAR  OF 
PRODUCTION,  SUBJECT;  DIFFERENCE  BETWEEN  EGG-SIZE  LIFE  MEAN  FOR  DAM  AND  FOR 
SIRE,  RELATIVE 

Coefficient  of  correlation  =  .012  ±  .052 

1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21  22 


1.0-1.5 

1                2 

1 

4 

1.5-2.0 

2 

1 

1 

1       2 

1            1 

9 

2.0-2.5 

4 

2 

2                4 

2       1 

7 

4223 

33 

2.5-3.0 

11 

5 

3217 

2       8 

3 

3214                                                         1 

53 

3.0-3.5 

6 

3 

3       4                1 

7       5 

2 

7           6111 

47 

3.5-4.0 

3 

2 

1        1 

2       1 

1 

3     1                                                1 

17 

4.0-4.5 

1                        1 

1 

3 

4.5-5.0 

0 

5.0-5.5 

0 

5.5-6.0 

1 

1 

6.0-6.5 

1 

6.5-7.0 

0 

7.0-7.5 

1 

1 

26     13     10      9      4     13     16     17     13     20     5  10 


110001001       169 


TABLE  2.  STANDARD  DEVIATION  OF  EGG  SIZE  DURING  SECOND  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-SIZE  LIFE  MEAN  FOR  DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  —  .28  ±  .08 


7       8      9    10     11     12     13     14     15     16     17     18     19 


1.5-2.0 

1 

1 

2 

2.0-2.5 

1                        2 

2 

2 

1 

22                                                                   1 

13 

2.5-3.0 

2       3 

1212 

2 

4 

4 

2        1       3 

27 

3.0-3.5 

2       2 

2        1 

3 

10 

3.5-4.0 

1 

1 

2 

4.0-4.5 

1 

1 

2 

000 


56 


210 


EARL  W.  BENJAMIN 


TABLE  3.  STANDARD  DEVIATION  OF  EGG  SIZE  DURING  THIRD  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-SIZE  LIFE  MEAN  FOR  DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  .13  ±.12 

1       2       3       4       5       6   •    7       8       9      10     11     12     13     14     15     16     17     18     19 


1.5-2.0 

1 

- 

1 

2.0-2.5 

1                1 

1 

3 

2.5-3.0 

1142 

131 

13 

3.0-3.5 

1        1                                                  1 

2                                                          1 

6 

3.5-4.0 

1                         1 

2 

4 

4.0-4.5 

0 

4.5-5.0 

0 

5.0-5.5 

j 

1 

5.5-6.0 

1 

1 

1302140 


43220000001 


20 


TABLE  4.  STANDARD  DEVIATION  OF  EGG  SIZE  DURING  FOURTH  YEAR  OF  PRODUCTION 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-SIZE  LIFE  MEAN  FOR  DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  —  .16  ±  .20 


10 


11 


12 


2.0-2.5 

1                                                                            1            1 

3 

2.5-3.0 

1                         1                                                               1 

3 

3.0-3.5 

2                         1 

3 

3.5-4.0 

0 

4.0-4.5 

1                                                                                                                                            1 

2 

TABLE  5.  STANDARD  DEVIATION  OF  EGG  SHAPE  DURING  FIRST  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-SHAPE  LIFE  MEAN  FOR  DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  .18  d=  .08 


.01    .02  .03   .04    .05    .06   .07 


.09    .10   .11    .12    .13    .14   .15   .16   .17   .18 


1.0-1.5 

1 

1 

1.5-2.0 

1 

1 

1 

1 

4 

2.0-2.5 

1       4 

3 

1 

1 

1 

1 

1        1 

1                                 1 

16 

2.5-3.0 

4       2 

2 

3 

2       1 

1 

2 

2 

3        1                1 

24 

3.0-3.5 

1       2 

1 

2 

2 

1                                         2 

11 

3.5-4.0 

1 

2 

2 

1 

4 

10 

4.0-4.5 

1 

1 

2 

4.5-5.0 

1 

1 

2 

G      9 


736542092520103 


70 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    211 

TABLE  6.  STANDARD  DEVIATION  OP  EGG  SHAPE  DURING  SECOND  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-SHAPE  LIFE  MEAN  FOR  DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  .14  ±  .10 

.01    .02    .03   .04  ..05    .06   .07   .08    .09   .10   .11    .12   .13    .14    .15   .16    .17    .18 


0.5-1.0 

!1 

1 

1.0-1.5 

0 

1.5-2.0 

1        1 

2 

2.0-2.5 

21111                                                           1 

7 

2.5-3.0 

11                        211                                          1                                          1 

8 

3.0-3.5 

3111                                 1                                          1 

8 

3.5-4.0 

1                                                                                    1                1 

3 

4.0-1.5 

1                                                                                    1 

2 

4.5-5.0 

0 

5.0-5.5 

1 

1 

533324310020310101            32 

TABLE   7.     STANDARD   DEVIATION  OF  EGG  SHAPE  DURING  THIRD  YEAR  OF  PRODUCTION, 

SUBJECT;    DIFFERENCE   BETWEEN   EGG-SHAPE    LIFE    MEAN   FOR   DAM  AND  FOR   SIRE, 

RELATIVE 

Coefficient  of  correlation  =  .13  ±  .18 

.01      .02     .03      .04     .05      .06     .07     .08      .09     .10     .11      .12     .13      .14 

2.0-2.5 

1                    1 

2 

2.5-3.0 

2111                                                                                    1 

6 

3.0-3.5 

1                                                                                                          1 

2 

3.5-4.0 

1     .               1                               l 

3 

4.0-4.5 

0 

4.5-5.0 

0 

5.0-5.5 

0 

5.5-6.0 

0 

6.0-6.5 

0 

6.5-7.0 

1 

1 

30221301000011                 14 

TABLE   8.     STANDARD  DEVIATION  OF  EGG  SHAPE  DURING  FOURTH  YEAR  OF  PRODUCTION, 

SUBJECT;    DIFFERENCE   BETWEEN   EGG-SHAPE    LIFE    MEAN  FOR   DAM   AND   FOR   SIRE, 

RELATIVE 

Coefficient  of  correlation  =  .45  ±  .20 

.01      .02     .03     .04      .05     .06      .07     .08      .09     .10     .11      .12     .13      .14 

1.5-2.0 

j 

1 

2.0-2.5 

2                    1 

3 

2.5-3.0 

1 

1 

3.0-3.5 

2                                                                                                                    1 

3 

3.5-^.0 

1                    1 

2 

10 


'212 


EARL  W.  BENJAMIN 


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STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   213 


TABLE  10.  STANDARD  DEVIATION  OF  EGG  COLOR  DURING  SECOND  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-COLOR  LIFE  MEAN  FOR  DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  .43  db  .07 

0.5  1.0  1.5  2.0  2.5  3.0  3.5  4.0  4.5  5.0  5.5  6.0  0.5  7.0  7.5  8.0  8.5  9.0  9.5 


0.25-0.50 

1 

1 

0.50-0.75 

1 

1 

0.75-1.00 

4       3 

7 

1.00-1.25 

2322                                 1 

10 

1.25-1.50 

312                21                2 

11 

1.50-1.75 

3                1                         122 

9 

1.75-2.00 

1                                          111 

5 

2.00-2.25 

112                        3 

7 

2.25-2.50 

1                                          1                         1 

3 

2.50-2.75 

2                                                  1                1 

4 

2.75-3.00 

1                                                  1 

2 

3.00-3.25 

1                                                  1 

2 

3.25-3.50 

1                                                  1 

2 

3.50-3.75 

0 

a.  75-4.  00 

1 

1 

4.00-4.25 

1 

1 

0 

4'.50-4.75 

1 

1 

4.75-5.00 

0 

5.00-5.25 

0 

5  .  25—5  .  50 

0 

5.50-5.75 

1 

1 

12     15 


4     11 


00000 


1        68 


TABLE  11.  STANDARD  DEVIATION  OF  EGG  COLOR  DURING  THIRD  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-COLOR  LIFE  MEAN  FOR  DAM  AND  FOR  SIRB, 
RELATIVE 

Coefficient  of  correlation  =  .52  zh  .13 


0.50-0.75 

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1 

1 

0.75-1.00 

211 

4 

1.00-1.25 

1                                                                   2 

3 

1.25-1.50 

1                         1 

3 

1.50-1.75 

2 

1.75-2.00 

1                1 

2 

2.00-2.25 

0 

2.25-2.50 

0 

2.50-2.75 

1 

1 

2.75-3.00 

1 

1 

3.00-3.25 

1 

1 

3.25-3.50 

1 

1 

3.50-3.75 

1 

1 

3.75-4.00 

0 

4.00-4.25 

0 

4.25-4.50 

0 

4.50-4.75 

0 

4.75-5.00 

0 

5.00-5.25 

1 



42120131 


0000000001 


21 


214 


EARL  W.  BENJAMIN 


TABLE  12.  STANDARD  DEVIATION  OF  EGG  COLOR  DURING  FOURTH  YEAR  OF  PRODUCTION, 
SUBJECT;  DIFFERENCE  BETWEEN  EGG-COLOR  LIFE  MEAN  FOR  -DAM  AND  FOR  SIRE, 
RELATIVE 

Coefficient  of  correlation  =  .55  ±  .15 

0.5  1.0  1.5  2.0  2.5  3.0  3.5  4.0  4.5  5.0  5.5  6.0  6.5  7.0  7.5  8.0  8.5  9.0  9.5 


1.00-1.25 

1                                                        4 

5 

1.25-1.50 

.    0 

1.50-1.75 

1 

1 

1.75-2.00 

1 

1 

2.00-2.25 

0 

2.25-2.50 

1 

1 

2.50-2.75 

0 

2.75-3.00 

0 

3.00-3.25 

0 

3.25-3.50 

1 

1 

3.50-3.75 

0 

3.75-4.00 

1 

1 

1100003040000000001 


10 


TABLE  13.     SUMMARY  OF  CORRELATIONS  BETWEEN  STANDARD  DEVIATION  OF  EGG  CHAR- 
ACTERS   DURING    EACH    OF    THE     FlRST    FOUR    YEARS    OF    PRODUCTION,     SUBJECT,     AND 

DIFFERENCE  BETWEEN  RESPECTIVE  LIFE  MEANS  FOB  DAM  AND  FOR  SIRE,  RELATIVE 


Selection 

Year  of  production 

Coefficient 
of 
correlation 

r 
Er" 

Number 
of  indi- 
viduals 

Size 

First 

012±  052 

0  23 

169 

Second 

-.28  ±.08 

3  50 

56 

Third  

.13  ±.12 

1  08 

29 

Fourth  

-.16  ±.20 

0.80 

11 

Shape 

First  

.18  ±.08 

2.25 

70 

Second     

.14  ±.10 

1.40 

32 

Third  
Fourth  

.13  ±.18 
.45  ±.20 

0.72 
2.25 

14 
10 

Color 

First  
Second.  .  .  . 

.13  ±.05 
43  ±  07 

2.60 
6  14 

174 
68 

Third  

52  ±  13 

4  00 

21 

Fourth  ....             .... 

.55  ±.15 

3.67 

10 

STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    215 

Inheritance  of  mean  egg  type 

The  correlations  shown  in  tables  14  to  22  and  summarized  in  tables  23 
and  24  indicate  a  distinct  positive  relation  between  the  mean  type  of 
either  or  both  parents  and  the  production  of  the  offspring.  In  table  23 

it  is  seen  that  =-  for  the  sire  ranges  from  3  to  18;  for  the  dam,  from  4 
.t^r 

to  22;  and  for  the  average  of  both  parents,  from  8  to  39.     In  table  24  it 

is  seen  that  tpr  ranges,  for  size,  from  4  to  10;  for  shape,  from  3  to  8;  and 
.Lr 

for  color,  from  18  to  39. 

TABLE  14.    TOTAL  AVERAGE  SIZE   (WEIGHT  IN  GRAMS)  OF  PRODUCTION  OF  THE  OFF- 
SPRING, SUBJECT;  SIZE  RECORD  FOR  SIRE,  RELATIVE 

Coefficient  of  correlation  =  .36  ±  .04 
45     46     47     48     49     50     51     52     53     54     55     56     57     58     59     60     61     62     63     64 


33 

1 

1 

38 

0 

40 

0 

42 

0 

41 

0 

46 

1 

1 

48 

3 

2       2 

1 

1 

1 

1 

1 

12 

50 

4 

3 

2 

2 

3 

1       2 

17 

52 

2 

2 

3 

5 

56                111 

2 

28 

51 

2       3 

2 

4 

7 

231                121 

5 

33 

53 

2 

1       2       2 

5 

2 

4 

13                        121 

6 

32 

53 

1 

1 

1 

2 

2 

11                311 

9 

23 

60 

1 

1 

1 

1 

3 

4 

11 

6J 

1 

1                1 

2 

5 

61 

1                        1 

3 

5 

66 

1                111 

4 

88 

0 

70 

o 

72 

0 

74 

1 

1 

13       0      0      0       5     13       3       0     13     15     24       9     10       4       1       8       8       5       0     33  173 


216 


EARL  W.  BENJAMIN 


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STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  217 


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218 


EARL  W.  BENJAMIN 


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STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HERTS'  EGGS  219 


TABLE  18.     TOTAL  AVERAGE  SHAPE  OF  PRODUCTION  OF  THE  OFFSPRING,  SUBJECT;  SHAPE 

RECORD  FOR  DAM,  RELATIVE 

Coefficient  of  correlation  =  .47  ±  .06 
58  59  60  61   62  63  64  65  66    67    68    69     70     71     72     73     74     75     76     77    78    79    80 


54 

1 

1 

1 

1 

~>S 

0 

GO 

0 

62 

0 

•U 

0 

fit', 

1                         1                             121 

6 

68 

22                1 

5 

70 

1                   312               53                       1                       1 

17 

72 

1                                            32272                       1311 

23 

74 

1121                                 12                      1 

9 

76 

312                                       11 

8 

78 

1                                                                        12 

4 

80 

!                                 1 

2 

102000200     126     10       0187002       734       02          76 


TABLE  19.    TOTAL  AVERAGE  SHAPE  OF  PRODUCTION  OF  THE  OFFSPRING,  SUBJECT;  AVERAGE 
SHAPE  RECORD  FOR  SIRE  AND  DAM,  RELATIVE 

Coefficient  of  correlation  =  .49  ±  .06 


. 


54  55  56  57  58  59  60  61  62  63  64  65  66  67  68  69  70  71  72  73  74  75 


* 

1 

1 

56 

1 

1 

58 

0 

60 

0 

62 

0 

64 

0 

66 

1112 

1 

6 

68 

1      1         2 

1 

5 

70 

1             1 

1   5 

4 

3      11 

17 

72 

1132 

2   4 

5 

3   1   1 

23 

74 

1 

2 

1 

3   1         1 

9 

76 

1 

3 

1 

3 

8 

78 

2 

2 

4 

80 

2 

2 

100000003032574     18     13     12       24       1       176 


220 


EARL  W.  BENJAMIN 


TABLE  20.    TOTAL  AVERAGE  COLOR  OF  PRODUCTION  OF  THE  OFFSPRING,  SUBJECT;  COLOR 

RECORD  FOR  SIRE,  RELATIVE 

Coefficient  of  correlation  =  .53  ±  .03 


1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 
7.5-8.0 
8.0-8.5 
8.5-9.0 


2.0     2.5     3.0    3.5      4.0    4.5      5.0       5.5       6.0     6.5       7.0      7.5      8.0       8.5 


3 

2 

3 

1 

9 

5 

5 

1 

2 

2 

15 

9 

1 

6 

5 

1 

11 

33 

2   10 

2 

1    8 

7 

8 

38 

1    5 

2 

1 

6 

1 

2     1 

19 

2 

3 

3 

11 

3 

2 

24 

1 

1 

2 

5 

1 

2 

12 

2 

7 

2 

1 

12 

1    1 

1    1 

1 

1 

6 

1 

1 

1 

3 

2 

2 

1 

1     3          3 

8 

3     4     6    13 

26 

1 

1 

1 

22          1 

8 

0 

1 

1 

40 


29       47 


12 


39 


6         17 


216 


TABLE  21.    TOTAL  AVERAGE  COLOR  OF  PRODUCTION  OF  THE  OFFSPRING,  SUBJECT;  COLOR 
RECORD  FOR  DAM,  RELATIVE 

Coefficient  of  correlation  =  .67  ±  .03 


1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 
7.5-8.0 
8.0-8.5 
8.5-9.0 


1.5    2.0    2.5     3.0     3.5     4.0     4.5       5.0       5.5       6.0 


i.5      7.0      7.5      8.0 


6 

3 

9 

8 

2 

1 

2 

2 

15 

5   10 

7 

3 

2 

1     3 

1 

1 

33 

1    3    7 

9 

4 

2 

4     1 

3 

4 

38 

212 

4 

2 

2 

2 

1     2               1 

19 

4 

7 

5 

2 

2     2 

2 

24 

6 

1 

1 

1 

1 

1 

12 

1    1 

3 

2 

1     2 

1 

1 

12 

1 

1 

1 

2 

6 

1 

1 

1 

3 

1 

1 

,  2 

1 

142 

8 

1 

1 

8    11     5 

26 

1 

1 

1 

2     1     2 

8 

0 

1 

1 

3       11       42      43       18       12 


11         11 


13 


14         14 


14 


216 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  221 


TABLE  22.   TOTAL  AVERAGE  COLOR  OF  PRODUCTION  OF  THE  OFFSPRING,  SUBJECT;  AVERAGE 
COLOR  RECORD  FOR  SIRE  AND  DAM,  RELATIVE 

Coefficient  of  correlation  =  .79  ±  .02 


1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5:5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 
7.5-8.0 
8.0-8.5 
8.5-9.0 


2.5       3.0       3.5       4.0       4.5       5.0       5.5       6.0       6.5       7.0       7.5 


3     2 

l 

2 

1 

9 

3     4 

1 

2 

4 

1 

15 

7     2 

7 

1 

10 

4 

1     1 

33 

6     2 

6 

8 

13 

2 

1 

38 

1     3 

2 

7 

3 

1 

2 

19 

3 

3 

11 

7 

24 

1     1 

4 

4 

2 

12 

4 

5 

1 

1 

1 

12 

2 

3 

1 

6 

1 

1 

1 

3 

1     1 

2 

1 

3     13 

8 

1 

1 

2     5    17 

26 

1 

2 

221 

8 

0 

1 

1 

22 


18         24 


45         49 


10 


12 


21 


216 


TABLE  23.  SUMMARY  OF  CORRELATIONS  BETWEEN  TOTAL  AVERAGE  CHARACTERS  OF 
PRODUCTION  OF  THE  OFFSPRING,  SUBJECT,  AND  AVERAGE  CHARACTERS  OF  PARENTS, 
RELATIVE 


Correlated  parentage 

Character  studied 

Coefficient 
of 
correlation 

r 
Er 

Number 
of  indi- 
viduals 

Sire 

Size 

36db  04 

9 

173 

Shape  .                 

21  ±  07 

3 

76 

Color 

53±  03 

18 

216 

Dam 

Size  

.22±  05 

4 

173 

Shape 

47  -t  06 

g 

76 

Color  

.67±.03 

22 

216 

Average  of  sire  and  dam 

Size 

42±  04 

10 

173 

Shape 

49±  06 

g 

76 

CoW  ,  

79±  02 

39 

216 

222  EARL  W.  BENJAMIN 

fABLE  24.    SUMMARY  GIVEN  IN  TABLE  23  ARRANGED  ACCORDING  TO  CHARACTERS 


Character 

Correlated  parentage, 

Coefficient 
of 
correlation 

r 
Er 

Number 
of  indi- 
viduals 

Size 

Sire                        

.36=t.04 

9 

173 

Dam                      

.22±.05 

4 

173 

Sire  and  dam      

.42db.04 

10 

173 

Shape 

Sire 

21  ±  07 

3 

76 

Dam 

47±  06 

8 

76 

Sire  and  dam                                              .  . 

.49db  06 

8 

76 

Color 

Sire  .                           

.53±.03 

18 

216 

Dam   .          

.67±.03 

22 

216 

Sire  and  dam  

.79±.02 

39 

216 

All  of  these  correlations  are  significant,  especially  since  they  arise 
from  a  random  population.  From  the  results  of  this  study,  it  would 
appear  that  the  quality  of  either  the  male  or  the  female  parent  will  affect 
the  type  of  egg  to  be  produced  by  the  offspring,  with  the  female  having 
slightly  greater  influence.  A  certain  character  is  of  much  greater  influence 
if  possessed  by  both  individuals  than  if  possessed  by  either  one  alone. 
This  does  not  agree  with  some  results  obtained  by  Pearl  (1912,  and  1915  a 
and  b)  in  dealing  with  quantity  of  production,  and  it  does  not  show  quite 
the  conditions  found  by  Goodale  (1918),  who  also  worked  with  the  quantity 
factor;  it  does  agree  fairly  closely,  however,  with  the  general  opinion 
prevailing  among  poultrymen. 

The  results  for  the  whole  experiment  relative  to  the  mean  character 
of  the  progeny  in  relation  to  the  respective  characters  of  the  sire  and 
the  dam,  are  charted  in  figures  12  to  17.  References  to  large,  small, 
round,  long,  brown,  or  white  parents  or  progeny  relate  to  the  quality  of  the 
eggs  produced  by  those  birds,  not  to  the  size,  shape,  or  color  of  the  birds. 
The  terms  large  and  small  refer,  respectively,  to  means  of  the  sizes  of 
eggs  produced  during  the  birds'  lifetime,  of  56  grams  or  more,  and  of 
less  than  56  grams;  the  terms  round  and  long  refer  to  means  of  the  index 
figures  of  the  eggs  produced  during  the  birds'  lifetime,  of  72  or  more,  and 
of  less  than  72,  respectively;  and  the  terms  brown  and  white  refer  to  means 
of  the  color  of  eggs  produced  during  the  birds'  lifetime,  of  3  or  higher, 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   223 


and   of  lower  than  3,  respectively.     The  exact  means   for  the  various 
groups  shown  in  figures  12  to  14  are  given  in  table  25: 


TABLE  25. 


MEAN  CHARACTERS  OF  BIRDS  AVAILABLE  FOR  USE  IN  CALCULATING  DATA 
FOR  FIGURES  12  TO  14 


Character 
type 

Mating 

Mean 
character 
for  sire 

Mean 
character 
for  dam 

Mean 
character 
for 
progeny 

Size 

Large  sire  and  small  darn  

59  6 

51.5 

54.3 

Small  sire  and  large  dam  

51.7 

60.6 

53.9 

Large  sire  and  large  dam  

60.3 

59.6 

57.2 

Small  sire  and  small  dam 

51  7 

51  7 

51.6 

Shape 

Round  sire  and  long  dam                      .... 

73  0 

69  3 

71.5 

Long  sire  and  round  dam                      

67  0 

75.4 

72.5 

Round  sire  and  round  dam  . 

73.0 

76.0 

75.0 

Long  sire  and  long  dam.                

65.4 

69.1 

71.0 

Color 

Brown  sire  and  white  dam  
White  sire  and  brown  dam 

4.81 
2  11 

2.34 
4  78 

3.00 
3.27 

Brown  sire  and  brown  dam 

4  56 

4  55 

3.75 

White  sire  and  white  dam 

2  34 

2  19 

2.60 

Large  Small  Prog- 
are    dam     eny 
(25)          (49) 


Small  Large  Prog- 
sire     dam     eny 
(18)         (81) 


Large  Large  Prog- 
sire     dam     eny 
(23)        '(41) 


Small  Small  Prog- 
sire     dam     eny 
(17)          (39) 


FlG.    12.      MEAN    SIZE    CHARACTERS   OF   SIRES,   DAMS,    AND   PROGENY   IN   ALL   MATINGS 

The  figures  in  parenthesis  designate  the  numbers  of  birds  available  for  the  respective  calculations 


224 


EARL  W.  BENJAMIN 


Shape 
index 


Round  Round  Prog- 
sire       dam     eny 
U)  (2) 

FlG.    13.      MEAN   SHAPE    CHARACTERS   OF   SIRES,    DAMS,    AND   PROGENY   IN   ALL   MATINGS 

The  figures  in  parenthesis  designate  the  numbers  of  birds  available  for  the  respective  calculations 


Round  Long  Prog- 
sire      dam     eny 
(3)  (9) 


Long  Round  Prog- 
sire      dam      eny 
(10)  (26) 


Long  Long  Prog- 
sire     dam     eny 
(16)          (46) 


Color 


Brown  White  Prog- 
sire      dam    eny 
(27)  (70) 


White  Brown  Prog- 
sire      dam     eny 
(12)  (30) 


Brown  Prown  Prog- 
sire      dam     eny 
(33)  (70) 


White  White  Prog- 
sire     dam     eny 
(27)  (29) 


FlG.    14.      MEAN    COLOR   CHARACTERS   OF   SIRES,   DAMS,   AND   PROGENY  IN    ALL    MATINGS 

The  figures  in  parenthesis  designate  the  numbers  of  birds  available  for  the  respective  calculations 

It  is  seen   in  figures  12  to    14  that  in  every  instance  in  which  one 
extreme  character  has  been  mated  with  another,  the  progeny  have  dis- 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    225 

played  a  character  between  the  two.  In  most  instances  in  which  the  sire 
and  the  dam  were  both  of  the  same  extreme  character,  the  progeny  dis- 
played a  character  nearer  to  normal  than  either  of  the  parents.  In  the 
case  of  small  size,  however,  this  tendency  was  reversed,  and  the 
character  for  the  progeny  from  two  small  parents  was  of  a  still  smaller 
type.  In  this  case  it  is  probable  that  tho  effect  of  the  size  of  body  was 
to  limit  the  size  of  the  eggs  (Benjamin,  1914). 

The  relative  effect  of  the  sire  and  the  dam  is  shown  clearly  in  figures 
15  to  17.  In  figure  15  it  is  seen  that  small  size  is  predominant  over  large 
size.  The  sire  will  transmit  small  size  to  the  progeny  much  more  strongly 
than  large  size.  In  the  instance  in  which  both  parents  are  large,  only 
58.6  per  cent  of  the  progeny  possess  the  "large"  character;  but  when 

58.6% 


Large  sire  Small  sire  Large  sire  Small  sre 

Small  dam  Large  dam  Large  dam  Small  dam 

FlG.    15.       RELATION    OF    PROGENY    SIZE    CHARACTERS    TO    SIRE    AND   DAM 

The  white  area  in  each  case  designates  the  proportion  of  progeny  showing  the  same  character  as  that  of 

the  sire 

both  parents  are  small,  81.9  per  cent  of  the  progeny  possess  the  "small" 
character.  The  two  parents  appear  here  to  have  about  equally  strong 
influence  in  transmitting  the  "small"  character.  The  predominance  of 
the  small  size  may  be  due  to  the  additional  physiological  factors  involved 
by  the  size  of  the  dam's  body  restricting  the  size  of  egg  which  can  possibly 
be  produced,  without  regard  to  any  inherited  tendencies.  A  hen  with 
a  large  body  can  produce  a  small  egg,  but  a  hen  with  a  small  body  cannot 
so  readily  produce  a  large  egg. 

The  question  of  the  inheritance  of  egg  shape  may  not  be  entirely  free 
from  the  physiological  complications  involved  in  the  study  of  egg  size. 
This  opinion  is  borne  out  by  figure  16.  The  dam  seems  to  have  nearly 
60  per  cent  of  the  influence  on  the  progeny.  The  fact  that  the  two  long 
parents  have  a  somewhat  higher  percentage  of  the  progeny  following 
their  type  than  do  the  two  round  parents,  would  lead  to  the  theory  that 


226 


EARL  W.  BENJAMIN 


the  length  character  is  somewhat  predominant  over  the  width;  other- 
wise one  would  expect  to  find  more  than  50  per  cent  of  round  progeny 
when  both  sire  and  dam  are  round. 

Both  the  size  and  the  shape  of  the  egg  seem  to  be  about  equally  trans- 
mitted to  the  progeny  by  the  dams  and  by  the  sires.     These  two  factors 


Round  sire 
Long  dam 


Long  sire 
Round  dam 


FlG.    16.      RELATION    OF    PROGENY    SHAPE    CHARACTERS   TO   SIRE    AND   DAM 

The  white  area  in  each  case  designates  the  proportion  of  progeny  showing  the  same  character  as  that  of 

the  sire 

appear,  however,  to  be  independent,  as  is  shown  by  an  entire  lack  of 
correlation  between  them  (Benjamin,  1912).  Such  a  condition  as  is 
found  here  is  the  reverse  of  what  might  be  expected  if  the  results  obtained 
by  other  workers  (Pearl  and  Curtis,  1916)  on  Barred  Plymouth  Rocks 
were  borne  out  with  the  strain  of  White  Leghorns  used  in  these  experi- 


Brown 
White  dam 


Brown  sire 
Brown  dam 


White  sire 
White  dam 


FlG.    17.      RELATION   OF    PROGENY    COLOR    CHARACTERS   TO   SIRE   AND   DAM 

The  white  area  in  each  case  designates  the  proportion  of  progeny  showing  the  same  character  as  that  of 

the  sire 

ments.     Pearl  and  Curtis  found  the  index  figure  and  the  weight  of  eggs 
to  be  negatively  correlated. 

The  study  of  the  color  inheritance  (fig.  17)  shows  about  equal  influences 
of  sire  and  dam.  When  both  parents  are  of  the  " white"  character, 
they  seem  to  be  able  to  transmit  their  character  more  definitely  than  when 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   227 

bath  are  of  the  "brown"  character,  but  this  difference  is  not  great. 
Neither  color  and  neither  parent  seem  to  have  a  predominance. 

These  results  are  an  accumulation  of  data  from  six  different  years, 
with  all  the  variations  in  conditions  that  must  always  occur.  Hence 
the  facts  shown  can  apparently  be  accepted  as  giving  undoubted  evidence 
of  the  inheritance  of  the  characters  in  question. 

Relation  of  egg  incubated  to  mean  egg  type  of  bird  hatched 

The  correlations  shown  in  tables  26  to  49,  and  summarized  in  tables 
50  and  51,  show  a  general  relationship  between  the  particular  type  of 
egg  incubated  and  the  type  of  egg  produced  by  the  chick  hatched,  both  for 

the  separate  years  of  the  bird's  production  and  for  its  life  mean.10  g- 

is  much  less  significant  for  these  studies  than  for  the  studies  of  the  relation 
existing  between  the  mean  productions  of  parents  and  progeny.  Apparently 
the  particular  type  of  egg  incubated  has  some  effect  on  the  type  of  egg 
which  the  offspring  will  produce,  but  not  so  much  effect  as  the  mean 
production  of  the  hen  which  laid  that  incubated  egg. 

In  this  study  the  coefficient  of  correlation  for  the  size  character,  as 
shown  in  table  50,  is  of  greater  significance  than  that  for  the  other  char- 
acters, as  is  the  case  in  all  of  the  work  here  reported.  The  shape  character 
shows  a  fair  degree  of  correlation. 

The  color  character  exhibits  a  peculiar  condition.  The  correlations  with 
the  pullets'  eggs  incubated,  for  the  first  and  second  years,  are  insignifi- 
cant; the  third-year  correlation  is  based  on  too  few  individuals  to  be  of 
much  value;  and  the  life-mean  correlation  shows  a  distinct  negative 
coefficient.  This  condition  is  probably  due  to  the  great  irregularity 
that  exists  in  the  coloration  of  successive  eggs  laid  by  most  individuals. 
Sufficient  proof  is  not  at  hand  to  warrant  the  conclusion  that  a  negative 
correlation  actually  exists  for  this  character,  but  it  is  believed  that  such 
a  negative  or  insignificant  correlation  may  be  expected,  due  to  the  irregu- 
larity of  the  material. 

10  The  terms  pullet  and  hen,  as  use!  in  this  memoir,  refer  to  female  birds  during  their  first  season  of 
production  and  during  their  later  seasons  of  production,  respectively. 


228 


EARL  W.  BENJAMIN 


TABLE  26.  MEAN  SIZE  (WEIGHT  IN  GRAMS)  OF  FIRST  YEAR'S  PRODUCTION  OF  BIRDS, 
SUBJECT;  SIZE  OF  PULLETS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED, 
RELATIVE 

Coefficient  of  correlation  =  .40  db  .063 


45        47        49        51        53        55        57        59        61        63 


65 


46 

1 

1 

48 

1    2    2 

2 

2 

9 

50 

1    1    5 

2 

1 

1 

11 

52 

1         1 

1 

4 

1 

2    1 

11 

54 

1    1 

5 

3 

1 

11 

56 

1 

3 

2 

3 

4 

3             1 

17 

58 

2 

1 

4 

1 

1 

1    2 

12 

60 

1 

2 

1 

4 

62 

1 

1 

1 

3 

64 

1 

1 

66 

1 

1 

13 


6        20        10        11 


81 


TABLE  27.     MEAN  SIZE  OF  SECOND  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  PUL- 
LETS' EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 


47 


Coefficient  of  correlation  =  .37  ±  .103 
49        51        53        55        57        59 


61 


50 

1 

1 

52 

1 

54 

1    1 

2 

1 

56 

1 

3 

1    1 

1 

58 

1 

2    1    1 

1 

60 

1 

2 

1    1    1 

62 

1    1 

64 

1 

1    1 

66 

68 

70 

1 

2 
1 
5 

7 
6 
6 
2 
3 
0 
0 
1 

33 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  229 


TABLE  28.    MEAN  SIZE  OF  THIRD  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  PUL- 
LETS' EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 


47 


Coefficient  of  correlation  =  .30  ±  .131 

49        51        53        55        57        59        61 


50 

1 

1 

52 

1    1                 1 

3 

54 

1        2        1 

5 

56 

1            1            1 

3 

58 

2    2 

4 

60 

1                 2 

3 

62 

1 

1 

64 

1 

1 

66 

0 

68 

0 

70 

0 

72 

0 

74 

1 

1 

22 


TABLE  29.    MEAN  SIZE  OF  FOURTH  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  PUL- 
LETS' EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .50  ±  .191 


47   49   51   53 

55   57   59 

50      1 

1 

52 

0 

54          1         1 

2 

56 

1 

1 

58 

0 

60 

1 

1 

62 

0 

64 

1 

1 

66 

0 

68                  1 

1 

1102 

0        1    7 

230 


EARL  W.  BENJAMIN 


TABLE  30.    MEAN  SIZE  OF  LIFE  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  PULLETS'  EGGS 
FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .37  =t  .065 


45 


47       49        51        53        55        57        59        61        63 


65 


46 

1 

48 

1    1    2 

2 

2 

50 

1    1    3 

1 

1 

1 

52 

1         2 

1    3 

1 

1 

54 

2    1 

7 

3    1    1 

56 

2 

2    2 

1 

331         1 

58 

1 

2    4 

3 

1    2 

60 

1 

1 

1 

1.1    1 

62 

2 

64 

1 

1 

1 

66 

68 

c 

70 

72 

74 

1 

13 


6       20        10 


10 


1 
8 
8 
9 
15 
15 
13 
6 
2 
3 
0 
0 
0 
0 
1 

81 


TABLE  31.    MEAN  SIZE  OF  FIRST  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  HENS' 
EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .31  ±  .065 


36 
38 
40 
42 
44 
46 
48 
50 
52 
54 
56 
58 
60 
62 
64 
66 


45   47 


49 


51   53   55   57   59   61   63   65   67   69 


1 

1 

0 

0 

0 

1 

1 

1 

1 

2 

1        1 

1 

1 

4 

3          2 

3 

8 

3 

2 

325 

1         1 

17 

2                     3 

2 

1        4        2 

2                  112 

20 

1                                2 

2 

1        2        4 

1         1           1 

15 

3 

2        2 

1                              1 

9 

1 

1        1 

2 

5 

1 

1 

1        1 

1                  1 

4 

1 

1 

13   11 


17   12 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  231 


TABLE  32.     MEAN  SIZE  OP  SECOND  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  HENS' 
EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .46  ±  .099 
45        47        49        51        53        55        57        59        61        63        65      67 


50 

1         12         1 

5 

52 

1             1 

2 

54 

1                          1 

2 

56 

1         1                      1 

3 

58 

212             1 

6 

60 

1             1                              1 

3 

62 

1 

1 

64 

1                     3 

4 

66 

0 

68 

1        1 

2 

70 

1 

*» 

1 

29 


TABLE  33.     MEAN  SIZE  OF  THIRD  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SIZE  OF  HENS' 
EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .65  ±  .123 


52  1          1                                                                                                                    2 

54  1           1 

56  1          1                                                                                   2 

58  1                                   1 

60  1                                                                        12 

62  0 

64  1                      1 

66  11 

10 


45   47   49   51   53   55    57 

59    61    63 

65 

1    1 
1    1 

1 

1 

1 

1 

1 

1 

232  EARL  W.  BENJAMIN 


TABLE  34.    MEAN  SIZE  OF  LIFE  PRODUCTION  OF  BIRDS,   SUBJECT;  SIZE  OF  HENS'  EGGS 
FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .34  ±  .063 


45    47    49    51     53    55    57    59    61      63      65      67      69      71      73      75 

36 
38 
40 
42 
44 
46 
48 
50 
52 
54 
56 
58 
60 
62 
64 
66 


1 

2 

2 

1 

- 

1              2      3 

4 

1 

1 

2 

3 

3 

5 

1         1 

1 

1 

3 

1 

4 

2       1 

1        2 

I      4 

1 

2 

4       1 

1 

1         1 

1 

1 

3 

1 

1 

1 

1 

2 

1 

1 

1 

1 

1 

1 

2 

2 

1 

1 

1 

1 

1 

0 
0 
0 
0 

1 

4 
10 

17 
16 
16 


2      3      5    11    11      9    16    14      3        5        3        3        4        0        0      1         90 


TABLE  35.     MEAN  SHAPE  OF  FIRST  YEAR'-S  PRODUCTION  OF  BIRDS,  SUBJECT;  SHAPE  OF 
PULLETS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .39  ±  .106 
68      69      70      71      72      73      74      75        76        77        78        79        80 


64                                1 

1 

63             1 

1 

2 

68                      1                 1 

1                                             3 

70                                                 1 

1          2                                             4 

72                      2                          3 

2        1        2 

10 

74                                          1 

2 

11                      16 

76 

1 

1 

78 

1 

1 

80 

1                                                         1 

13124 

352 

2          4          1          0          1         29 

STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  233 


TABLE  36.     MEAN  SHAPE  OF  SECOND  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SHAPE  OP 
PULLETS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .23  ±  .192 


69        70        71 


72 


73       74       75       76       77 


68 

1                    11                    1 

4 

70 

11                                         11 

4 

72 

1                               1 

2 

74 

0 

76 

1 

1 

11 


TABLE  37.     MEAN  SHAPE  OF  LIFE  PRODUCTION  OF  BIRDS,  SUBJECT;  SHAPE  OF  PULLETS' 
EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .43  ±  .102 


68      69      70      71      72      73      74      75       76        77        78 


79        80 


66 

1                 1                          1 

3 

68 

1 

1 

70 

11                  1                   12 

6 

72 

2                          3211                     1 

10 

74 

1                           11                     11                     1 

6 

76 

1 

1 

78 

1 

1 

80 

1 

1 

29 


234 


EARL  W.  BENJAMIN 


TABLE  38.     MEAN  SHAPE  OF  FIRST  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SHAPE  OF 
HENS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .34  =b  .083 
61     62    63    64    65    66    67    68    69    70    71     72    73    74    75    76    77    77+ 


54 

1 

56 

58 

60 

62 

64 

66 

1                                              121 

68 

11112 

1 

70 

11                              11 

2 

72 

1              11              1                     2132 

1              2      2 

74 

1                                    2 

1211 

76 

1 

2              1 

78 

1 

1     4 

80 

1 

0323346737 


1 
0 
0 
0 
0 
0 
5 
7 
6 
17 
8 
4 
3 
1 

52 


TABLE  39.     MEAN  SHAPE  OF  SECOND  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SHAPE  OF 
HENS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 


67        68 


Coefficient  of  correlation  =  .47  ±  .101 
69        70        71        72        73        74        75 


76        77 


66 

1                    111 

4 

68 

1 

1 

70 

1                               1 

1 

1          1 

5 

72 

1                    1 

2          2 

6 

74 

1 

2          1 

1                     1 

6 

76 

1 

1 

1          1 

4 

78 

1 

1 

2          1 


27 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   235 


TABLE  40.     MEAN  SHAPE  OF  THIRD  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  SHAPE  OF 
HENS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .52  ±  .142 


69        70        71        72        73 

74        75        76 

77 

^54           1 

1 

56 

0 

58 

0 

60 

0 

62 

0 

64 

0 

66           1 

1 

68                                                      1 

1 

70                                                    1 

1          1 

1 

4 

72 

1 

1 

2 

74                      1                     1 

1 

3 

21012 

0         2          1 

3 

12 

TABLE  41.    MEAN  SHAPE  OF  LIFE-  PRODUCTION 

OF  BIRDS,  SUBJECT 

;  SHAPE  OF  HENS'  EGGS 

FROM  WHICH  RESPECTIVE  BIRDS 

WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .31  ±  .084 

61  or 

less    62  63  64    65    66     67    68    69    70 

71    72    73    74 

75    76 

77    77+ 

54 

1 

1 

56 

0 

58 

0 

60 

0 

62 

0 

64                                                                1 

1 

66           1                                      11 

1 

1                 5 

68                                                                1 

1      1 

3 

70                                  1111 

2      2 

3      1 

12 

72                1          1                     1                     2 

1211 

1      2 

3                16 

74                                                        1 

1      3 

1 

6 

76 

1              1 

2 

1                  5 

78 

1 

1 

1                  3 

80 

1           1 

110110.3233 

4673 

7     4 

6      1         53 

236 


EARL  W.  BENJAMIN 


TABLE  42.     MEAN  COLOR  OF  FIRST  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF 
PULLETS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  — .12  ±  .07 
1234567 


1.0-1.5 

1 

2 

3 

1 

1.5-2.0 

1 

7 

3 

2                                1 

2.0-2.5 

7 

8 

3 

2.5-3.0 

4 

12 

2 

4                     1 

3.0-3.5 

6 

3 

1 

3          1 

3.5-4.0 

1 

1 

1 

4.0-4.5 

1 

1 

2 

4.5-5.0 

3 

3 

1 

1 

5.0-5.5 

1 

2 

5.5-6.0 

2 

2 

6.0-6.5 

6.5-7.0 

7.0-7.5 

1 

1 

28        38        20 


10 


7 

14 

18 

23 

14 

3 

4 

8 

3 

4 

0 

0 

2 

100 


TABLE  43.     MEAN  COLOR  OF  SECOND  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF 
PULLETS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .002  ±  .105 
1          234          5          6          7 


1.0-  1.5 
1.5-  2.0 
2.0-  2.5 
2.5-  3.0 
3.0-  3.5 
3.£-  4.0 
4.0-  4.5 
4.5-  5.0 
5.0-  5.5 
5.5-  6.0 
6.0-  6.5 
6.5-  7.0 
7.0-  7.5 
7.5-  8.0 
8.0-  8.5 
8.5-  9.0 
9.0-  9.5 
9.5-10.0 
10.0-10.5 


1 

1 

2 

1 

4 

2 

2 

1          1                                1 

3 

2 

1          1 

2 

1 

3 

1          1 

1 

2 

1 

1 

2 

1 

• 

1 

- 

1 

13        16 


1 
3 
5 
7 
7 
3 
5 
1 
3 
0 
3 
1 
1 
0 
0 
0 
0 
0 

1 

41 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  237 


TABLE  44.    MEAN  COLOR  OF  THIRD  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF 
PULLETS'  EGOS  FROM  WHICH  RESPECTIVE  BIROS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .57  =t  .15 


1.6-2.0 

1 

2.0-2.5 

2.5-3.0 

2 

3.0-3.5 

1 

1 

3.5-4.0 

1          1 

4.0-4.5 

1 

4.5-5.0 

5.0-5.5 

5.5-6.0 

1 

TABLE  45.     MEAN  COLOR  OF  LIFE  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF  PULLETS 
EGOS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  —  .26  ±  .06 


1.0-1.5 

1 

2 

2 

5 

1.5-2.0 

1 

6 

2                    2 

11 

2  0-2.5 

5 

6 

3                                         1 

15 

2.5-3.0 

5 

11 

2         5                    1 

24 

3.0-3.5 

5 

4 

1         2         1 

13 

3.^4.0 

2 

4 

3 

9 

4.0-4.5 

1 

1 

2          1 

5 

4.5-5.0 

3 

3 

1                    1 

8 

5.0-5.5 

2 

2 

4 

5.5-6.0 

2 

1 

3 

6.0-6  5 

0 

6.5-7.0 

0 

7.0-7.5 

1 

1 

2 

7.5-8.0 

1 

1 

28        38        20 


100 


238 


EARL  W.  BENJAMIN 


TABLE  46.    MEAN  COLOR  OF  FIRST  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF 
HENS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 


1      2      3 


Coefficient  of  correlation  =  .20  ±  .08 
4      5      6     7    8    9    10  11  12  13  14  15  16  17  18  19  20 


1.0-1.5 

1 

1.5-2.0 

2 

2 

4 

1 

2.0-2.5 

1 

3 

3 

2              1 

2.5-3.0 

5 

3 

3 

3             2 

3.0-3.5 

1 

2 

1 

1       1       1 

3.5-4.0 

3 

2 

1 

4.0^.5 

1 

1 

2 

2      1 

4.5-5.0 

1 

1 

5.0-5.5 

1 

2 

1 

5.5-6.0 

1 

6.0-6.5 

6.5-7.0 

1 

7.0-7.5 

7.5-8.0 

1 

8.0-8.5 

8.5-9.0 

1 

15    15    17      9      4      400000000100001 


1 

9 
10 
16 

7 
6 
7 
2 
4 
1 
0 
1 
0 

1 

0 

1 

66 


TABLE  47.    MEAN  COLOR  OF  SECOND  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF 
HENS' EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .31  db  .10 


1    2    3    4    5    6    7    8    9  10  11  12  13    14    15    16    17    18    19  20 


1.0-1.5 

1 

1.5-2.0 

1     1 

2.0-2.5 

1231          1 

2.5-3.0 

1 

3.0-3.5 

2               1 

3.5-4.0 

2 

4.0-4.5 

1          1 

4.5-5.0 

111                                                                                                  1 

5.0-5.5 

1          1 

5.5-6.0 

1 

6.0-6.5 

6.5-7.0 

1 

7.0-7.5 

7.5-8.0 

8.0-8.5 

8.5-9.0 

1 

5484230000000      0      1      0      0      0      01 


1 
2 
8 
1 
3 
2 
2 
4 
2 
1 
0 
1 
0 
0 
0 
1 

28 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  239 


TABLE  48.     MEAN  COLOR  OF  THIRD  YEAR'S  PRODUCTION  OF  BIRDS,  SUBJECT;  COLOR  OF 
HENS'  EGGS  FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .17  ±  .20 
1    2    3    4    5    6    7    8    9  10   11   12    13   14   15    16    17    18    19   20 


1.0-1.5 

1 

1 

1.5-2.0 

1 

1 

2.0-2.5 

1 

1 

2.5-3.0 

1 

1 

3.0-3.5 

0 

3.5-4.0 

1 

1 

4.0-4.5 

1                                                             1                                 1 

3 

4.5-5.0 

1 

1 

5  0-5.5 

1 

1 

5.5-6.0 

. 

0 

6.0-6.5 

0 

6.5-7.0 

0 

7.0-7.5 

1 

1 

1141110000000      0      1      0      0      0      01 


11 


TABLE  49.  MEAN  COLOR  OF  LIFE  PRODUCTION  OF  BIRDS,  SUBJECT:  COLOR  OF  HENS'  EGOS 
FROM  WHICH  RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .28  ±  .08 
1234567     8     9  10  11  12   13    14  15   16    17    18   19    20 


1.0-1 

5 

1 

1.5-2 

0 

1 

1 

3 

1 

2.0-2 

5 

2 

4 

4 

1 

2.5-3 

0 

5 

3 

3 

2          2 

3.0-3 

5 

1 

2 

2          2 

3.5-4 

0 

3 

•2 

1     1 

4.^4 

5 

1 

1 

2 

2    1 

4.5-5 

0 

1 

1 

1 

2 

5.0-5 

5 

3 

5.5-6 

0 

6.0-6 

5 

1                                  1 

6.5-7 

0 

7.0-7 

5 

7.5-8 

0 

1 

1 

8.0-8 

5 

8.5-9.0 

1 

15  15  18    9440000000      0      1      0      0      0      01 


1 
6 
11 
15 
7 
7 
7 
5 
3 
0 
2 
0 
0 
2 
0 
1 

67 


240 


EARL  W.  BENJAMIN 


TABLE  50.  SUMMARY  OF  CORRELATIONS  BETWEEN  CHARACTER  MEANS  FOR  PRODUCTION 
FOR  SEPARATE  YEARS  AND  FOR  LIFE,  SUBJECT,  AND  CHARACTERS  FOR  PARENT  EGGS 
INCUBATED  FROM  PULLETS  OR  FROM  HENS,  RELATIVE 


Character 

Year  of 
production 
(means  for) 

Pullets'  eggs  incubated 

Hens'  eggs  incubated 

Coefficient 
of 
correlation 

r 
17 

Number 
of  indi- 
viduals 

Coefficient 
of 
correlation 

r 
Er" 

Number 
of  indi- 
viduals 

Size 

First 

.40  ±.033 
.37  ±.103 
.30  ±.131 
.50  ±.191 
.37  ±.065 

6.3 
3.6 
2.3 

2.6 
5.7 

81 
33 
22 

7 
81 

.31±.065 
.46±.099 
.65±.123 

4.8 
4.6 
5.3 

88 
29 
10 

Second  
Third  
Fourth  
Life  

.34±.063 

5.4 

90 

Shape 

First  
Second  
Third  
Life  

.39  ±.106 
.23  ±.192 

''43'±'.102 

3.7 

1.2 

29 
11 

.34±.083 
.47±.101 
.52±.142 
.31±.084 

4.1 
4.7 
3.7 
3.7 

52 
27 
12 
53 

4.2 

29 

Color 

First  
Second 

-.12  ±.07 
.002±.105 
.57  ±.15 
-.25  ±.06 

1.7 
0.02 
3.8 
4.3 

100 
41 
9 
100 

.20±.08 
.31±.10 
.17±.20 

.28±.08 

2.5 
3.1 
0.8 
3.5 

66 
28 
11 
67 

Third  

Life 

TABLE  51.     SUMMARY  OF  — -  FROM  TABLE  50 


Year  of 
production 

Character 

Hir 

Pullets'  eggs 
incubated 

Hens'  eggs 
incubated 

First 

Size  
Shape  
Color  

6.3 
3.7 
1.7 

4.8 
4.1 
2.5 

Second 

Size 

3.6 
1.2 
0  02 

4.6 
47 
3.1 

Shape 

Color  

Third 

feize  
Shape  

23 

5.3 
3.7 
0.8 

Color  

3.8 

Life 

Size  
Shape 

5.7 
4.2 
43 

5.4 
3.7 
3.5 

Color 

STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  241 

The  summary  in  table  51  groups  the  figures  for  the  factor  of  significance, 
-p-'  according  to  years  and  life  means.  There  is  a  more  significant  cor- 
relation between  the  life  mean  of  the  offspring  production  and  the  type 
of  parent  egg  incubated,  than  between  the  production  of  any  of  the  separate 
years  and  the  incubated  egg.  This  means  that  the  egg  incubated  affects 
the  mean  type  of  egg  produced  during  the  whole  life  of  the  bird  hatched, 
to  a  greater  extent  than  it  affects  the  pullet-year  production  or  the  pro- 
duction of  any  other  single  year. 

There  is  a  strong  correlation,  as  shown  in  tables  52  to  54,  when  a  study 
is  made  of  the  relationship  between  the  individual  eggs  incubated  and  all 


TABLE  52.     SIZE  (WEIGHT   IN   GRAMS)  .OP  EGGS    LAID   BY   BIRDS,    SUBJECT;  SIZE   OF 
EGGS  FROM  WHICH  RESPECTIVE   BIRDS  WERE    HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .458  db  .007 

46   48   50   52   54   56   58   60   62   64   66  68  70  72   74 


28-30 

1 

30-32 

1 

32-34 

1 

34-36 

3 

1 

36-38 

4 

6 

2 

38HIO 

3 

6 

1 

40-42 

2 

8 

1 

5 

1 

5 

42-44 

10 

8 

3 

27 

2 

2 

1 

44^6 

41 

32 

11 

63 

3 

3 

9 

5 

46-48 

68 

45 

23 

82 

28 

12 

30 

3 

11 

48-50 

77 

108 

32 

89 

32 

30 

76 

4 

5 

44   1 

50-52 

45 

155 

39 

41 

45 

70 

124 

8 

11 

76 

52-54 

26 

129 

65 

29 

79 

98 

110 

29 

25 

137   8 

54-56 

15 

69 

79 

25 

143 

120 

91 

51 

27 

153  12 

1 

56-58 

3 

42 

45 

24 

129 

87 

65 

1  104 

35 

157   1 

1 

58-60 

1 

24 

28 

17 

75 

50 

59 

74 

59 

94   4 

1 

60-62 

6 

33 

13 

28 

36 

38 

1   38 

46 

79   2 

62-64 

1 

6 

10 

2 

15 

28 

35 

30 

116 

31 

64-66 

6 

1 

5 

17 

22 

17 

85 

16 

66-68 

1 

4 

1 

49 

1 

1 

68-70 

1 

1 

19 

70-72 

1 

13 

72-74 

j 

1 

3 

74-76 

2 

1 

1 
1 

1 

4 

12 

10 

22 

53 

167 

302 

498 

614 

735 

786 

694 

486 

320 

274 

169 

57 

22 

14 

5 

3 


300  646  376  41 S  585  557  667    2  356  500  811  28   0 


5,250 


the  individual   eggs   produced   by   the   respective   birds   hatched!     The 
factor  -gj  equals,  for  size,  shape,  and  color,  respectively,  65,  20,  and  16. 

This  is  significant  and  suggests  the  same  relative  degrees  of  inheritance 
as  are  found  in  other  studies  in  this  investigation. 


242 


EARL  W.  BENJAMIN 


The  comparable  coefficients  of  variability,  calculated  on  the  basis  of 
unit  classes,  for  the  eggs  used  in  compiling  tables  52  to  54  are:  for  size 
(table  52),  20  per  cent;  for  shape  (table  53),  10  per  cent;  for  color  (table  54), 
74  per  cent.  The  greater  irregularity  in  the  color  of  eggs  as  compared 


TABLE  53. 


54-  56 

56-  58 
58-  60 
60-  62 
62-  64 
64-  66 
66-  68 
68-  70 
70-  72 
72-  74 
74-  76 
76-  78 
78-  80 
80-  82 
82-  84 
84-  86 
86-  88 
88-  90 
90-  92 
92-  94 
94-  96 
96-  98 
98-100 


SHAPE  OF  EGGS  LAID  BY  BIRDS,  SUBJECT;  SHAPE  OF  EGGS  FROM  WHICH 
RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .204  ±  .01 


64        66        68        70        72 


74        76 


78 


1 

1 

1 

6 

1 

3 

2 

2 

2            21 

1 

7 

7 

8 

65 

6 

24 

16 

16 

146 

17 

71 

58 

34 

132 

38 

222 

152 

80 

1   143 

44 

310 

196 

146 

97 

80 

397 

175 

211 

39 

43 

355 

122 

148 

21 

13 

175 

59 

39 

5 

4 

48 

4 

10 

1 

9 

3 

4 

1 

9 

1 

3 

1 

1 

1 

1 

2 

1 

1 

1   680   247   1,637   796   701 


1 

0 

2 

14 

46 

127 

326 

624 

840 

961 

707 

307 

71 

17 

11 

3 

1 

0 

2 

1 

2 

0 

2 

4,065 


with  the  other  characters  undoubtedly  accounts  for  the  results  in  this 
one  correlation  with  the  pullets'  eggs  incubated.  The  coefficients  of 
correlation  for  the  study  of  the  mean  production  with  the  hens'  eggs  are 
positive  for  all  characters  and  years.  The  color  correlation  is  about  as 
significant  as  the  shape  correlation. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  243 


TABLE  54.    COLOB  OF  EGOS  LAID  BY  BIRDS,  SUBJECT;  COLOR  OP  EGGS  FROM  WHICH 
RESPECTIVE  BIRDS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .145  rfc  .009 
1         2        .3         4         5         6         7         8 


1 
2 
3 
4 

5 
6 
7 
8 

9 
10 
11 
12 
13 
14 
15 
10 
17 


143 

238 

40 

182 

175 

117 

10 

33 

396 

298 

168 

188 

206 

107 

26 

16 

215 

174 

173 

183 

227 

56 

42 

31 

68 

119 

137 

110 

173 

32 

33 

14 

27 

71 

62 

85 

86 

24 

12 

22 

15 

44 

47 

47 

41 

8 

12 

21 

7 

18 

28 

31 

21 

7 

1 

6 

12 

14 

26 

44 

17 

2 

1 

14 

1 

5 

18 

15 

26 

2 

16 

4 

5 

26 

20 

19 

3 

2 

7 

1 

2 

21 

19 

30 

7 

3 

8 

1 

19 

5 

10 

2 

1 

6 

8 

9 

11 

2 

2 

1 

16 

6 

2 

1 

1 

1 

892   995   791   938  1,050   367   144   190 


938 

1,405 

1,101 

686 

389 

235 

119 

130 

83 

86 

91 

37 

39 

23 

3 

1 

1 


5,367 


66-68 
62-64 
58-60 
54-56 
50-52 
46-48- 
42-44- 
38-40 
34-36 
30-32 


66-68 
62-64 
IMi 

54-5« 
50-52 
46-48 
42-44 
38-40 
34-36 


58-60 
54-56- 


r 


I 


20  24    28     1     5     9    13    17    21    25    29     2     «     10    14    18    22    28     1      5     9     13    17    21    25    29     2 
December  January  February  March  April 

PlG.    18.      VARIATION   OF   SIZE    (WEIGHT   IN   GRAMS)    OF   SUCCESSIVE   EGGS  LAID  DURING 

EARLY   PULLET   PRODUCTION 
The  squares  blocked  in  black  indicate  the  days  on  which  eggs  were  laid  by  the  respective  pullets 


244 


EARL  W.  BENJAMIN 


Relation  of  eggs  incubated  to  types  of  eggs  produced  by  the  respective  birds 

hatched 

Some  further  features  of  the  relationship  existing  between  the  types  of 
eggs  incubated  and  the  egg  types  produced  by  the  respective  birds  hatched, 
are  shown  in  figures  18  to  25.  These  figures  represent  only  a  small  part 
of  the  available  material  resulting  from  the  study,  and  are  used  here 
merely  to  show  typical  conditions. 


Grams 


Weeks        6       11      16     21     26     31     36     41      46     51      56     61      66     71      76     81      86     91      96     101 

FlG.    19.      VARIATION  OF  SIZE    (WEIGHT  IN  GRAMS),  BY  WEEKLY  AVERAGES,  OF  EGGS  PRO- 
DUCED BY  DAM  FOR  TWO  YEARS  AND  BY  PROGENY  DURING  EARLY  PULLET  PRODUCTION 

The  heavy  horizontal  line  in  each  division  represents  the  character  of  the  parent  egg  incubated;  the 
heavy  curve  represents  the  production  of  the  chick  hatched;  the  light  curve  represents  the  production 
of  the  progeny  of  the  chick.  The  dotted  lines  indicate  that  no  eggs  were  produced  during  the  periods 
which  they  cover 

Pullets  8882F  and  8939F,  illustrated  in  figure  18,  are  from  small  eggs, 
but  pullet  8872F  is  from  a  large  egg.  It  is  evident  that  the  tendency 
is  for  a  pullet  to  produce  eggs  of  the  same  size  as  the  egg  from  which 
she  was  hatched.  Sometimes  small  eggs  are  obtained  from  hens  that 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  245 


FlG.  20.      SHADOW  PHOTOGRAPHIC  RECORD  OF  RELATION  BETWEEN  SIZE  OF  EGG  INCUBATED 
AND    SIZE    OF    EGGS    PRODUCED    BY   THE    RESULTANT    CHICK 

Each  row  of  progeny  production  shows  twelve  eggs,  which  were  selected  at  regular  intervals  during 
the  respective  year's  production.  All  eggs  were  photographed  each  year,  but  only  twelve  eggs  for  each 
year  could  be  represented  in  this  group 


246 


EARL  W.  BENJAMIN 


ordinarily  lay  large  eggs,  and  vice  versa;  this  probably  accounts  for  the  low 
correlation  in  studies  of  mixed  flocks,  while  the  study  of  separate  matings 
shows  more  definite  results.  The  heavy  curve  for  line  3916F  in  figure  19 
represents  the  record  for  the  bird  whose  early  pullet  daily  record  is  shown 
as  8882F  in  figure  18. 

The  photographic  record,  figure  20,  shows  the  relative  sizes  of  eggs 
produced  by  line  8224F,  one  of  the  largest  lines,  and  by  line  3916F,  one 
of  the  smallest  lines.  The  difficulty  of  observing  the  fine  differences  in 
size,  except  by  careful  measurements,  is  seen  from  this  figure.  Under 
line  3916F  is  shown  another  record  of  the  production  of  8882F. 


20  24  28  1   5   9  13  17  21  25  29  2   6  10  14  18  22  26  1   5   9  13  17  21  25  29  2 


FIG 


January  February  March  April 

21.       VARIATION    OF     SHAPE     OF    SUCCESSIVE    EGGS    LAID    DURING    EARLY     PULLET 

PRODUCTION 

The  squares  blocked  in  black  indicate  the  days  on  which  eggs  were  laid  by  the  respective  pullets 


In  figures  21  and  22  are  shown  the  daily  and  weekly  fluctuations  of 
shape.  A  photographic  record  of  two  of  the  first-year  inheritance  results 
for  the  shape  character  is  shown  in  figure  23.  Both  of  the  lines  shown  in 
figure  23  are  shown  also  in  figure  22.  Neither  the  shape  nor  the  size  of 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    247 

eggs  has  a  large  coefficient  of  variability,  and  this  fact  is  reflected  in  the 
curves  and  in  the  photographic  record. 


Shape 
index 


1 


Weeks        6      11      16     21     26      31      36    41      46     51      56     61     66    .71     76      81     86     91     %     101 

FlG.    22.      VARIATION  OF   SHAPE,  BY  WEEKLY   AVERAGES,   OF   EGGS   PRODUCED  BY  DAM  FOR 
TWO  YEARS  AND  BY  PROGENY  DURING  EARLY  PULLET  PRODUCTION 

The  heavy  horizontal  line  in  each  division  represents  the  character  of  the  parent  egg  incubated;  the 
heavy  curve  represents  the  production  of  the  chick  hatched;  the  light  curve  represents  the  production 
of  the  progeny  of  the  chick.  The  dotted  lines  indicate  that  no  eggs  were  produced  during  the  periods  which 
they  cover 

The  color  character  has  a  much  higher  coefficient  of  variability,  as  may 
be  observed  from  figures  24  and  25.  The  pullets  included  in  figure  24 
were  all  of  the  brown-egg  type,  but  in  figure  25  both  brown-egg  and  white- 
egg  types  are  shown.  In  these  figures  there  seems  to  be  a  tendency  for 
the  type  of  egg  produced  by  the  original  pullet  hatched,  and  her  later 
offspring,  to  resemble  the  original  egg  incubated.  The  writer  can  explain 
the  negative  or  practically  zero  correlation  for  the  color  character  in  the 


248 


EARL  W.  BENJAMIN 


FlG.  23.   SHADOW  PHOTOGRAPHIC  RECORD  OF  RELATION  BETWEEN  SHAPE  OF  EGG  INCU- 
BATED AND  SHAPE  OF  EGGS  PRODUCED  BY  THE  RESULTANT  CHICK 

Each  row  of  progeny  production  shows  twelve  eggs,  which  were  selected  at  regular  intervals  during  the 
respective  year's  production.  All  eggs  were  photographed  each  year,  but  only  twelve  eggs  for  each  year 
could  be  represented  in  this  group 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    249 

data  previously  reviewed,  only  by  the  high  coefficient  of  variability  and 
the  probability  that  many  abnormal  eggs  are  incubated  instead  of  the 
normal  type  for  the  respective  dam. 


20    24    28 
December 


5      9     13    17    21    25 
January 


2      6     10    14    18    22    26    1 

February 


9      13    17    21 


29     2 
April 


FlG.  24.      VARIATION  OF  COLOR  OF  SUCCESSIVE  EGGS  LAID  DURING  EARLY  PULLET 

PRODUCTION 

The  squares  blocked  in  black  indicate  the  days  on  which  eggs  were  laid  by  the  respective  pullets 


EARL  W.  BENJAMIN 


*••••  ••*•  ••••••••••• 


:::  si  :  :  :::  :::  ::  ::;::  :  :  :  ::  :::  :  :  :::::  ::::  :  ::  : 
•••••  •••••  sssss  :::::  :::::  ::::::::::  :::::  ::  : 


iSSSS  5SSSS  ""I  SSSSS  SSSSS ! 


•  s  s ; : • s ss i  sis  s sssssssssii 


VARIATION  OF  COLOR,  BY  WEEKLY   AVERAGES,  OF  EGGS    PRODUCED    BY  DAM    FOR 
TWO    YEARS    AND   BY    PROGENY   DURING    EARLY    PULLET    PRODUCTION 

The  heavy  horizontal  line  in  each  division  represents  the  character  of  the  parent  egg  incubated;  the 
heavy  curve  represents  the  production  of  the  chick  hatched;  the  light  curve  represents  the  production  of 
the  progeny  of  the  chick.  The  dotted  lines  indicate  that  no  eggs  were  produced  during  the  periods  which 

MISCELLANEOUS  STUDIES 

A  few  studies  were  made  in  addition  to  those  relating  solely  to  the  degree 
of  inheritance  existing  for  the  size,  shape,  and  color  characteristics.  These 
are  discussed  in  the  following  pages. 

Relationship  of  size  and  shape  of  eggs 

A  study  was  made  of  a  mixed  assortment  of  pullets'  eggs  (table  55), 
which  showed  practically  a  zero  correlation.  This  does  not  agree  with 
results  reported  by  Pearl  and  Curtis  (1916).  Some  individuals,  and  some 
different  strains  and  breeds,  may  possess  characteristics  the  reverse  of  those 
of  the  strain  of  Single  Comb  White  Leghorns  used  in  these  experiments. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  251 


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252 


EARL  W.  BENJAMIN 


Incubation  effects  of  egg  type 

In  the  1911  hatch  the  incubation  records  of  the  eggs  were  studied  in  rela- 
tion to  the  egg  type.  These  studies,  as  shown  in  tables  56  and  57,  do  not 
indicate  any  definite  relationship  between  egg  type  and  incubation  record. 

TABLE  56.    A  STUDY  OF  EGG  TYPES  AND  INCUBATION  RECORDS 


Type  of  eggs 
incubated 

Per  cent 
of  infertile 
eggs 
for  each 
character 

Per  cent 
of 
total 
infertile 
eggs 

Per  cent 
of 
dead  germs 
for  each 
character 

Per  cent 
of 
total 
dead 
germs 

Per  cent 
hatched 
for  each 
character 

Per  cent 
of 
total 
chicks 
hatched 

Large  

6 

11 

54 

10.5 

40 

12 

Medium  

4 

7 

68 

13 

28 

8 

Small 

8 

14 

40 

8 

52 

15 

Long 

6 

11 

54 

10  5 

40 

12 

Normal 

8 

14 

54 

10  5 

38 

11 

Round  

16 

29 

58 

11 

23 

8 

Brown-tinted  

4 

7 

54 

10.5 

42 

13 

Cream-tinted  

4 

7 

70 

14 

23 

8 

Chalk-white  

0 

0 

58 

11 

42 

13 

TABLE  57.     RELATION  OF  SIZE  OF  EGGS  INCUBATED    TO  THEIR  INCUBATION  RECORDS 


Weight  of  eggs 
incubated 
(grams) 

Infertile  eggs 

Dead  germs 

Chicks  hatched 

Total 
number 
of  eggs 

Number 

Per 

cent 

Number 

Per 

cent 

Number 

Per 
cent 

42^4 

2 
0 
1 
1 
1 
3 
2 
2 
4 
3 
5 
3 
1 
0 
0 
0 

22 

4 
6 
8 
7 
14 
4G 
37 
40 
30 
22 
23 
14 
3 
1 
0 
1 

44 
60 
30 
44 
56 
66 
60 
61 
57 
50 
62 
58 
60 
100 

"166 

3 
4 

18 
8 
10 
21 
23 
24 
19 
19 
9 
7 
1 
0 
0 
0 

33 
40 
67 
50 
40 
30 
37 
36 
36 
43 
24 
29 
20 

9 
10 
27 
16 
25 
70 
62 
66 
53 
44 
37 
24 
5 
1 
0 
1 

44-46 

46-48 

4 
7 
4 
4 
3 
3 
7 
7 
14 
13 
20 

48-50  
50-52  .  .           

52-54  
54-56  
56-58  

58-60  

60-62 

62-64 

64-66..            .    .. 

66-68  
68-70  
70-72  
72-74  

Total  

28 

256 

166 

450 

STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  253 


In  table  57  the  eggs  incubated  were  grouped  according  to  size  and 
incubation  results,  in  order  to  see  whether  any  effect  on  the  incubation 
record  exists.  No  definite  effect  is  shown  by  the  data  available  here. 

Relative  variability  of  the  productions  of  successive  years 

The  standard  deviation  for  all  the  eggs  produced  each  year  by  each 
of  the  available  hens  was  studied,  in  order  to  learn  whether  there  is  an 
approach  to  a  definite  egg  type  for  the  eggs  produced  by  a  hen  as  she 
becomes  older.  The  data  from  this  study  are  collected  in  figures  26  and 


3.20 


3.00 


2.40 


tfs~  _  Co/or  *  3e/ec//b/r  ^/^6-_._ 


2.20 


200- 


1.60 
1.40 
1.20 
1.00 

0  SO 
Year  1st  2d  3d  4th  5th  6th 

FlG.  26.      STANDARD   DEVIATIONS   FOR   SUCCESSIVE   YEARS,   GROUPED   AS   TO    CHARACTER 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 

27.  In  figure  26  the  studies  are  segregated  into  the  three  character 
groups.  The  reduction  of  the  number  of  birds  available  for  study  in 
the  fifth  and  sixth  years  makes  the  data  for  these  years  of  doubtful  value, 
altho  the  number  of  eggs  used  for  each  bird  is  in  each  case  sufficient  to 
make  the  standard  deviation  of  real  value. 


254 


EARL  W.  BENJAMIN 


In  figure  27  the  data  for  the  three  characters  are  combined  both  by  a 
weighted  and  by  an  ordinary  average.  This  figure  does  not  show  the 
definite  tendency  toward  a  reduction  in  the  "variability  which  is  claimed 
by  some  other  investigators  (Pearl,  1909),  altho  if  the  data  for  the 
fifth  and  sixth  years  could  be  given  as  much  value  in  this  discussion  as 
is  given  to  the  data  for  the  first  four  years,  a  straight  line  fitted  to  the 
curve  would  show  a  distinct  reduction  in  the  standard  deviation.  The 
unweighted  averages  are  shown  in  figure  27  because  if  it  can  be  considered 
that  the  standard  deviations  calculated  for  the  respective  character 

of  lhree  characters, 


2  80-, 

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-FlG.    27.       STANDARD    DEVIATIONS    OF    ALL    CHARACTERS    FOR    SUCCESSIVE    YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 

groups  are  based  on  a  sufficient  number  of  individuals  to  be  trustworthy, 
none  of  these  characters  should  be  handicapped  in  the  average  if  it  hap- 
pened that  a  less  number  of  individuals  were  available  for  that  particular 
character  than  for  the  others.  This  is  especially  true  since  this  is  a 
comparison  of  standard  deviations  based  on  a  grouping  according  to  classes 
of  widely  different  values. 

Variations  in  types  of  eggs  produced  during  successive  months  and  years 

The  study  of  the  variations  of  eggs  produced  during  successive  months 
and  years  was  carried  on  with  birds  that  began  to  lay  in  different  months, 
as  noted  in  table  58. 

The  time  of  beginning  to  lay  is  varied  enough  in  the  data  used  here  to 
nearly  eliminate  seasonal  effects. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   255 


TABLE  58.     PERCENTAGE  OP  EACH  YEAR'S  FLOCK  BEGINNING  TO  LAY  IN  THE  RESPECTIVE 
MONTHS  FROM  NOVEMBER  TO  JUNE,  INCLUSIVE 


Month  when 
laying  began 

Percentage  of  year's  flock  that  began  laying  in  respective  months 

First 
year  of 
pro- 
duction 

.    Second 
year  of 
pro- 
duction 

Third 
year  of 
pro- 
duction 

Fourth 
year  of 
pro- 
duction 

Fifth 
year  of 
pro- 
duction 

Sixth 
year  of 
pro- 
duction 

November  
December  
January 

0.3 
21.7 
29.6 
28.2 
11.2 
9.0 

1.1 

8.6 
28.0 
28.4 
22.6 
9.7 
"I.I 
0.5 

5.6 

2.6 
2.6 
43.6 
48.6 
2.6 

6.2 
28.4 
46.9 
18.5 

5.6 
33.3 
49.9 
5.6 

February 

20.0 
80.0 

March              

April  .             

May  

June 

Size  character 

The  variations  in  the  mean  size  of  the  eggs  produced  during  the  successive 
months  by  the  size-selection  birds  are  shown  in  figures  28  to  31.  These 
curves  are  made  up  by  calculating  the  mean  for  the  first  month's  pro- 
duction of  the  first  year,  the  second  month's  production  of  the  first  year, 
and  so  on  for  the  succeeding  months  and  years  for  each  hen  used, 
and  then  finding  the  mean  for  all  available  hens  at  each  period.  Data 
for  eleven  months  of  each  year  were  available  for  a  sufficient  number 
of  birds  to  make  the  figures  reasonably  reliable. 

The  size  of  the  eggs  produced  by  pullets  increases  fairly  regularly 
during  the  year,  but  no  real  increase  in  the  size  of  the  eggs  produced  during 
the  later  j^ears  of  production  can  be  observed.  It  may  seem  that  this 
statement  is  disproved  by  figure  30,  but  a  glance  at  figure  28  shows  that 
the  size  of  the  first  year's  production  increases  so  rapidly  that  it  causes 
the  mean  size  to  increase  slightly. 

All  seasonal  effects  are  eliminated  in  these  studies,  the  birds  being 
arranged  in  accordance  with  the  month  when  they  began  laying  each 
year,  irrespective  of  the  particular  month  which  that  happened  to  be.  It 
would  seem  that  the  wide  fluctuations  after  the  ninth  month  in  figure  28, 
and  after  the  seventh  month  in  figure  29,  may  be  due  to  the  fact  that  too 
few  birds  were  available  for  study;  but  an  apparent  tendency  for  the  size 
of  the  egg  to  increase  rapidly  near  the  end  of  the  laying  season  is  observed. 


256 


for 


EARL  W.  BENJAMIN 

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Month  1st           2d              3d             4th            5th            6th             7th             8t 

FlG.   28.      MONTHLY   VARIATION   IN   SIZE   OF   EGGS   PRODUCED 
YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for 

Sec  one/  years      T/?/s&  t/e&s?         feoc/r/fy  t/e&ry       f/tfh  U£ 
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Month  1st  2d  3d  4th  5th  6th  7th  8th  9th  10th         llth 

FlG.    29.      MONTHLY  VARIATION  IN   SIZE   OF   EGGS   PRODUCED    DURING   A   PERIOD    OF   SIX 

YEARS 
The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  257 


It  should  be  noted  that  the  individuals  whose  data  are  used  for  the 
later  months  of  the  year,  shown  in  figures  28,  29,  and  30,  are  those  that 
laid  during  the  longest  period  and  were  very  likely  to  be  the  highest  pro- 
ducers (Rice,  1914).  This  would  indicate  an  agreement  with  Curtis 


34 
Month  1st 


2d 


3d 


7th 


8th 


9th 


10th 


llth 


FlG.    30.      MONTHLY   VARIATION   IN   SIZE    OF   EGGS    PRODUCED   DURING   A   PERIOD   OF   SIX 

YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 

The  curve  representing  the  birds  having  a  life  mean  of  45  or  less  does  not  lie  entirely  within  that  range 

because  the  whole  six-years  data  on  which  the  life  mean  is  based  is  not  available  in  monthly  means  for 

this  chart 

(1914  a)  and  Hadley  (1919)  to  the  effect  that  the  conditions  causing  the 
production  of  a  great  many  eggs  will  also  cause  the  production  of  large 
eggs.  In  order  to  see  whether  the  results  shown  in  figures  28,  29,  and  30 
were  due  to  the  selection  of  high-producing  birds  from  the  low  producers, 
as  suggested  above,  figure  31  was  constructed  for  five  individuals  which 


258 


EARL  W.  BENJAMIN 


began  laying  in  December  and  continued  laying  for  about  the  same  period 
as  the  others  (until  August).  No  material  difference  can  be  observed 
between  the  types  of  curves  shown  in  figure  31,  and  those  shown  in 
figures  28,  29,  and  30.  There  seems,  then,  to  be  no  marked  error  due 
to  the  possible  selection  of  birds  in  the  study  of  the  random  flocks,  and 
it  is  probable  that  the  curves  for  heavy  producers  are  not  materially 
different  from  those  for  lower  producers. 


Dec. 


Jan. 


Feb. 


March 


April 


May 


June 


Aug. 


FlG.    31.       MEAN    MONTHLY    SIZE    RECORDS    FOR  FIVE   NORMAL  INDIVIDUALS    FOR  A  PERIOD 

OF    FIVE    YEARS 

After  the  great  increase  in  the  size  of  the  eggs  from  the  first  to  the  second 
year,  there  seems  to  be  a  gradual  decrease  in  the  size  of  the  eggs  produced 
during  successive  years.  This  last  statement  does  not  agree  with  the 
results  of  Curtis  (1914  a). 

No  decreased  size  of  the  eggs  produced  at  the  beginning  and  at  the  end 
of  the  litter  is  observed,  as  claimed  by  Fere  (1898b)  and  Curtis  (1914  a), 
and  there  is  no  appreciable  difference  in  the  variations  for  the  birds  laying 
large,  medium,  and  small  eggs  (fig.  30). 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    259 

Shape  character 

In  order  to  study  the  relative  monthly  and  yearly  shapes  of  eggs  pro- 
duced, the  data  for  shape  selection  were  prepared  for  figures  32  to  35  in 
the  same  way  that  the  data  for  size  selection  were  prepared  for  figures 
28  to  31.  There  is  shown  a  tendency  for  the  eggs  produced  each  year, 
even  in  the  pullet  year,  to  have  a  gradually  increasing  index  until  the 
fifth  or  sixth  month  of  production,  after  which  this  index  gradually  decreases 
until  the  season's  production  ceases  (fig.  32). 


Index 


Month    1st 


llth 


FlG.    32.      MONTHLY   VARIATION    IN    SHAPE    OF   EGGS    PRODUCED  DURING  A  PERIOD  OF  SIX 

YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 

According  to  figure  32,  the  eggs  produced  during  the  pullet  year  are 
of  practically  the  same  shape  as  those  produced  in  later  years.  The 
difference  may  be  considered  insignificant.  The  reader  should  be  warned 
against  erroneous  interpretation  of  the  fifth  and  sixth  years'  production 
shown  in  figure  33,  because  of  the  very  few  individuals  available  for  study 
for  those  years. 

As  indicated  in  figure  34,  there  seems  to  be  no  radical  difference  between 
the  variation  of  the  groupings  according  to  the  life  means  of  the  birds. 
Where  slight  differences  are  shown,  these  may  usually  be  considered  as 
being  due  to  an  insufficient  number  of  individuals  available  for  study. 

The  five  birds  recorded  in  figure  35  showed  no  distinct  character  different 
from  those  shown  in  figures  32  to  34. 


230 


EARL  W.  BENJAMIN 


years    T/7/rrf  t/ecrrs   /E>t/rf/7  i/ears  f/ffft  years 


T)th 


Gth 


7th 


8th 


9th 


10th 


llth 


FlG.    33. 


MONTHLY   VARIATION    IN    SHAPE  OF    EGGS    PRODUCED    DURING  A  PERIOD  OF    SIX 

YEARS 


The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  261 


Index 


75 


65 

Month  1st 


9th 


10th 


llth 


FlG.   M.      MONTHLY   VARIATION   IN   SHAPE    OF   EGGS   PRODUCED   DURING  A  PERIOD  OF  SIX 

YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 

The  curve  representing  the  birds  having  a  life  mean  of  60-65  does  not  lie  entirely  within  that  range 

because  the  whole  six-years  data  on  which  the  life  mean  is  based  is  not  available  in  monthly  means  for 

this  chart 


262 


EARL  W.  BENJAMIN 


Index 
** 

75 


<r/  years        Second  years         7/7/rd  years 


Dec. 


Jan. 


Feb. 


March 


April 


June 


July 


Aug. 


FlG.    35.       MEAN   MONTHLY  SHAPE  RECORDS  FOR  FIVE  NORMAL  INDIVIDUALS    FOR  A  PERIOD 

OF    FIVE    YEARS 

These  results  do  not  agree  with  deductions  to  be  gained  from  Curtis 
(1914  a)  or  from  Thompson  (1908).  It  would  appear  from  these  results  that 
the  tension  of  the  oviduct  wall  may  gradually  relax  during  the  first  five  or 
six  months  of  the  bird's  production  each  year,  and  then  increase  again  as  the 
season  closes,  causing  at  first  a  rounding  of  the  egg  and  later  a  lengthening. 

Color  character 

The  study  of  the  monthly  production  as  to  the  variations  of  color  is 
summarized  in  figures  36  to  39.  There  is  a  definitely  increased  amount 
of  pigment  in  the  eggs  produced  by  the  hens  after  their  pullet  year  as 
compared  with  their  first  year's  production  (fig.  36).  There  is  a  distinct 
tendency  for  the  eggs  to  become  whiter  as  the  production  continues  for 
the  first  five  or  six  months,  and  then  to  become  more  tinted  again  toward 
the  end  of  the  season's  production.  It  would  seem  that  the  amount  of 
pigment  is  decreased  during  the  period  of  most  abundant  egg  production. 

As  shown  in  figure  37,  there  is  no  distinct  and  gradual  increase  in  the 
pigmentation  of  the  eggs  from  the  second  to  the  sixth  year's  production, 
but  during  each  year  when  enough  birds  are  available  for  the  data  to  be 
considered  of  value,  there  is  a  tendency  for  the  same  montlily  fluctuations 
as  are  exhibited  in  figure  36.  The  grouping  of  the  birds  according  to  their 
life  means  in  figure  38  shows  the  same  monthly  fluctuations  as  were 
previously  observed. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  263 


rfeor?  for  first                   /fee//?  for  second  fo 

Color    uearS  prOG/MCf  _  __  _  _     3/X//7   years  -amdi/tr/- 

\\  fs?4ij 

\ 

5  4       \ 

\ 

50™        ^ 

4.  fi  - 

\        \ 

*          \ 
\ 

(137) 

L(29) 

44- 

\ 

\ 

/ 

\ 

3 

4  2  - 

\ 

. 

/ 

V 

/ 

M 

\ 

\ 

/ 

\ 

/ 

M 

\ 

\ 

XI33) 

/75) 

\    y 

^6) 

36- 

1 

|,24.) 

^x^ 

^s^ 

V 

3.4- 
32- 

— 

.(^.^i^XdLag) 

I 

Q  21) 

g2&L^^ 

1®  — 

(70)         _, 

7     T 

30- 

i^7L  ^ 

(126) 

fioi)      -** 

••    — 

(9) 

2.8- 
26- 

^*  ^.^ 

'J®;—  '  — 

** 

\ 

\ 

2.4  - 
2.2. 

\V2) 

^L9 

Month  1st  2d  3d  4th  5th  6th  7th  8th  9*h  10th          llth 

FlG.   36.      MONTHLY  VARIATION   IN    COLOR   OF  EGGS   PRODUCED   DURING  A  PERIOD  OF  SIX 

YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 


264 


EARL  W.  BENJAMIN 


Color 


hr      7h/sv/  yecrrjr      /^c/rfS?  years     f/ffh  year* 
proc/uc/—  •  -  -procfisc£—  .  —  .  —proc/vct  •  •  •  .  . 


1-6 
Month  1st 


3d 


4th 


5th  6th  7th  8th  9th  10th         llth 

FlG.   37.      MONTHLY   VARIATION   IN    COLOR  OF   EGGS    PRODUCED    DURING  A  PERIOD  OF  SIX 

YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 


STUDY  OF  SELECTIONS  FOB  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  265 


B/rds 


Color 


Month  1st 


2d 


3d  4th  5th  6th  7th  8th    "      9th    "  "  10th" llth 

FlG.   38.      MONTHLY  VARIATION  IN    COLOR  OF   EGGS   PRODUCED   DURING  A  PERIOD  OF  SIX 

YEARS 

The  figures  in  parenthesis  designate  the  number  of  birds  available  for  the  respective  calculations 


266 


EARL  W.  BENJAMIN 


The  results  of  this  study  agree  in  general  with  the  findings  of  other 
workers,  already  discussed. 

The  record  of  five  individuals  in  figure  39  agrees  in  general  with  the 
records  in  figures  36  to  38. 


Color 


Dec. 


Jan. 


Feb.  March  April  May  June 


July  Aug. 


FlG.    39.      MEAN   MONTHLY  COLOR  RECORDS  FOR  FIVE  NORMAL  INDIVIDUALS  FOR  A  PERIOD 

OF   FIVE    YEARS 

Variations  in  types  of  successive  individual  eggs 

An  opportunity  is  furnished  by  figures  18,  21,  and  24  (pages  243,  246, 
and  249)  to  observe  how  the  types  of  successive  eggs  may  be  affected  by 
the  general  type  of  the  bird  and  the  rate  of  laying. 

In  figure  18  it  may  be  noted  that  in  nearly  every  instance  when  two  or 
more  eggs  are  laid  on  successive  days,  the  sise  gradually  diminishes  until 
the  bird  rests  for  one  or  more  days,  when  the  size  of  the  next  egg  is  again 
larger.  This  agrees  with  many  more  charts  constructed  for  this  same 
character,  and  is  in  entire  accordance  with  Curtis  (1914  a). 

A  study  of  figure  21,  which  agrees  in  general  with  other  charts  constructed 
for  the  shape  character  but  not  reproduced  here,  reveals  the  fact  that  in 
a  large  proportion  of  the  instances  when  two  or  more  eggs  are  laid  in 
succession,  the  egg  laid  later  is  rounder  than  the  one  laid  earlier.  About 
60  per  cent  of  the  cases  showed  an  increase  in  the  index,  25  per  cent  showed 
no  change,  and  15  per  cent  showed  a  decrease.  This  condition  may 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    267 


result  from  the  less  tension  exerted  by  the  oviduct  wall  on  the  second 
egg  when  it  closely  follows  an  earlier  one.  After  the  bird  has  rested  for 
a  day  er  two,  the  oviduct  wall  regains  its  tension  and  the  next  egg  is  longer. 
The  egg  color,  for  the  birds  that  were  studied  in  this  regard,  seemed 
to  be  gradually  intensified  in  eggs  kid  on  successive  days  (fig.  24).  About 
50  per  cent  of  the  cases  showed  an  intensification  of  color,  25  per  cent 
showed  no  change,  and  25  per  cent  showed  a  decrease  of  color. 

Variations  in  types  of  eggs  produced  in  different  calendar  months 
Since  it  is  known  that  the  commercial  eggs  received  in  the  markets 
vary  somewhat  from  month  to  month  as  to  their  average  size  and  color, 
and  possibly  as  to  their  shape,  it  was  thought  well  to  ascertain  what 
information  could  be  obtained  on  this  point  from  the  data  at  hand.  These 
variations  for  size,  shape,  and  color,  respectively,  are  illustrated  in  figures 
40,  41,  and  42. 

The  results  shown  in  figure  40  do  not  agree  with  those  of  Hadley  (1919), 
but  tend  instead  to  agree  in  general  form  with  figures  28,  29,  and  30. 

Grama 
62 


\ 


\ 


Z. 


Feb. 


Nov. 


March  April  May  June  July  Aug.  Sept.  Oct. 

FlG.  40.       MEAN    MONTHLY  VARIATION  IN  SIZE  OF  EGGS  PRODUCED  IN  CERTAIN  CALENDAR 
!_    MONTHS   FOR  A  PERIOD  OF  SIX  YEARS.      RECORD  OF  TEN  INDIVIDUALS  BEGINNING  TO 
LAY   IN   FEBRUARY 

No  increase  of  egg  size  during  the  period  of  heavier  production  can  be 
observed  here,  as  found  by  Hadley  (1919)  with  White  Plymouth  Rocks. 

The  results  shown  in  figures  41  and  42  agree  closely  with  the  results 
previously  obtained  for  mixed  flocks,  and  need  no  further  comment 
here, 


268 


EARL  W.  BENJAMIN 


Index 

^^ 

/ 

X 

71.0- 
70  5  - 

-? 

S 

X 

- 

^\ 



70  0  - 

/ 

^-^| 

^^ 

69.5- 

/ 

69  0  - 

/ 

68.5- 

.S^ 

68.0 

/ 

67  5 

/ 

67  0 

/ 

66  5 

/ 

66.0 

' 

Jan 


Feb.    lF~  March 


April 


May 


June 


July 


Aug. 


Oct. 


FlG.  41.  MEAN  MONTHLY  VARIATION  IN  SHAPE  OF  EGGS  PRODUCED  IN  CERTAIN  CALENDAR 
MONTHS  FOR  A  PERIOD  OF  SIX  YEARS.  RECORD  OF  TEN  INDIVIDUALS  BEGINNING  TO 
LAY  IN  JANUARY 


Color 

v 

^*^ 

\ 

/ 

3  8- 

\ 

/ 

3  7- 

\ 

/ 

3  6- 

V 

/ 

3  5  «. 

\ 

/ 

3.4- 

\ 

/ 

3  3- 

V 

/ 

3.2- 

\ 

/ 

3.1- 

^  ^ 

/ 

\ 

/ 

3  0- 

v 

/ 

V 

/ 

2.9- 

N 

/ 

\ 

/ 

Feb.     -  .    March 


April 


May 


June 


July 


Aug. 


Sept. 


Oct. 


FlG.  42.  MEAN  MONTHLY  VARIATION  IN  COLOR  OF  EGGS  PRODUCED  IN  CERTAIN  CALENDAR 
MONTHS  FOR  A  PERIOD  OF  SIX  YEARS.  RECORD  OF  TEN  INDIVIDUALS  BEGINNING  TO 
LAY  IN  FEBRUARY 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  269 

Relation  between  vigor  of  the  chick  and  size  of  the  egg  from  which  it  was  hatched 
In  1911-12  a  separate  record  of  the  vigor  of  the  chicks,  as  well  as  of  their 
weight,  was  made  for  the  first  forty  weeks  of  their  lives.  The  vigor  was 
^recorded  in  four  classes:  Very  Poor  (V.P.),  Poor  (P),  Good  (G),  Very 
Good  (V.G.).  Correlation  tables  such  as  table  59  were  constructed 

TABLE  59.     VIGOR  OF  CHICKS  AT  THE  AGE  OF  FOUR  WEEKS,  SUBJECT;  WEIGHT  (IN  GRAMS) 
OF  EGGS  FROM  WHICH  THE  RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .381  =fc  .064 
44^6  46^8  48-50  50-52  52-54  54-53  56^58  58-60  60-62   62-64  64-66 


V.  P. 

1 

1 

p. 

1          3 

1 

1 

1 

1 

1 

9 

G. 

5 

1 

6 

5 

4 

3 

1 

2 

27 

V.G. 

5 

4 

8 

8 

2 

8 

4        4 

43 

1 


x 


0 


11        14 


10 


80 


for  each  four  weeks  of  the  chicks'  lives.  A  summary  of  the  results  of 
rthe  correlation  tables  (space  for  which  cannot  be  taken  here)  is  given  in 
table  60.  In  this  table  the  respective  weight  correlations  also  are  shown. 

TABLE  60.  SUMMARY  OF  COEFFICIENTS  OF  CORRELATION  FOUND  IN  STUDYING  THE 
RELATION  OF  THE  WEIGHT  AND  VIGOR  OF  THE  CHICKS,  SUBJECT,  AND  THE  WEIGHT  OF 
THE  EGGS  FROM  WHICH  THE  RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 


Coefficient  c 

f  correlation 

Number 

Chick  vigor 

Chick  weight 

viduals 

1  day 

* 

.844±.021 

82 

4  weeks 

.381±.064 

.461±.060 

80 

8  weeks                                                      

.331±.036 

.311±.067 

82 

12  weeks                                          

.334±.069 

.362±.068 

75 

16  weeks                                            

.338±.070 

.380±.068 

72 

20  weeks                             

.159±.077 

.263±.073 

73 

24  weeks                         

.176±.077 

.308±.072 

73 

28  weeks 

174±  081 

.296±  077 

65 

32  weeks 

296±.080 

.509±.064 

61 

36  weeks 

075  ±.087 

.392±.074 

60 

40  weeks 

.110±.093 

.397^.079 

51 

*  The  vigor  was  not  recorded  at  the  one-day-old  period,  because  it  was  impossible  to  designate  the  dif- 
ferent classes  at  this  early  age. 

In  recording  the  data  for  these  vigor  studies,  a  special  effort  was  made 
to  be  sure  that  the  record  for  vigor  was  made  independently  of  the  record 


270 


EARL  W.  BENJAMIN 


for  weight.  Of  course  these  two  factors  are  likely  to  be  very  closely 
associated.  The  weight  correlations  are  much  more  distinct  than  those 
for  vigor  during  most  of  the  year.  The  vigor  correlations  decreased 
after  the  early  weeks,  until  some  very  severe  winter  weather  just  previous 
to  the  thirty-sixth  week's  recording.  After  the  thirty-sixth  week,  how- 
ever, abnormally  early  spring  weather  prevailed,  the  vigor  of  all  birds- 
improved  wonderfully,  and  the  correlation  entirely  disappeared. 

From  the  observations  just  noted,  it  seems  that  the  test  of  the  vigor 
of  a  chick,  that  is  to  say,  when  the  size  of  the  parent  egg  is  of  real 
benefit,  comes  during  the  season  of  greatest  hardship  to  the  birds.  The 
weights  are  not  affected  by  the  seasonal  conditions  quite  so  definitely  as  is 
the  vigor. 

Relation  between  male  and  female  weights  for  chicks  of  the  same  age 
During  the  first  forty  weeks  of  the  1911  hatch,  and  the  first  seventy-six 
weeks  of  the  1912  hatch,  the  male  and  female  weights  were  averaged 


TABLE  61. 


CONSTANTS   REPRESENTING  X  IN   THE    FORMULA:    FEMALE  WEIGHT  :  MALE 
WEIGHT  :  :  X  :  1 


1911  offspring 

1912  offspring 

Age 

Constant 

Age 

Constant 

4  weeks  

.89 

1  day  
4  weeks  

.97 

72 

8  weeks  

.91 

8  weeks  

.84 

12  weeks  

.81 

12  weeks  

.86 

16  weeks 

78 

16  weeks   . 

88 

20  weeks 

75 

20  weeks 

87 

24  weeks 

75 

24  weeks 

* 

28  weeks 

.88 

28  weeks  ... 

95 

32  weeks  
36  weeks  ... 

.89 
.92 

32  weeks  
33  weeks  

.91 
95 

40  weeks  

.90 

40  weeks  

.94 

44  weeks 

85 

48  weeks 

83 

v 

52  weeks 

89 

56  weeks  
60  weeks  
64  weeks  '.  
68  weeks  

.84 
.81 

.82 
.85 

72  weeks 

82 

76  weeks 

.83 

X 

*  No  male  weights  were  obtained  at  this  age  in  1912. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS    271 

separately,  and  for  each  four-weeks  period  a  figure  was  obtained  to  rep- 
resent x  in  the  following  ratio: 

Female  weight  :  male  weight  ::  x  :  1 

LA.  list  of  all  such  constants  obtained  is  shown  in  table  61.  In  studying 
[correlations  for  the  weeks  shown  in  table  61  for  the  1911  offspring,  and 
[for  the  one-day-old  period  of  the  1912  offspring,  the  male  weights  were 
multiplied  by  their  respective  constants  and  used  with  the  female 
[weights.  After  the  above  periods,  and  for  all  other  offspring,  no  male 
weights  were  used.  These  constants  correspond  rather  closely  to  the  con- 
stant 0.93  representing  the  same  ratio  for  human  stature  in  mature  per- 
sons, found  by  Galton.11 

Relation  between  size  of  the  chick  and  size  of  the  egg  from  which  it  was  hatched 

A  preliminary  study  was  made  of  the  1911  and  1912  offspring,  before 

the  records  for  the  later  years  were  available,  to  determine  the  relation 

between  the  size  of  the  chick  and  the  size  of  the  egg  from  which  it  was 


8   16  24  32  40  48  56   64  72  80  88  96  104  112  120  128  138  144  152  160  168  176  184  192  200  208  216  224 
-K  4   12   20  28  36  44  52  60  68  76  84  92  100  108  lift  124  132  140  148  156  164  172  180  188  196  204  212  220 

FlG.  43.      GRAPHIC  RECORD  OF  ~  FOR  19!  I  OFFSPRING,  igi2  OFFSPRING,  AND  ALL  BIRDS 
AVAILABLE   DURING  THE   PERIOD   OF  THE   EXPERIMENT 

Sizes  of  birds  at  four- weeks  periods  during  their  life,  subject;  sizes  of  eggs  from  which  the  respective 
chicks  were  hatched,  relative 


11  Galton,  Francis.    Natural  inheritance,  p.  78.     1889. 


272 


EARL  W.  BENJAMIN 


hatched  (Benjamin,  1912  and  1914).     The  coefficients  of  correlation  for 
these  preliminary  studies  are  summarized  in  table  62  and  in  figure  43. 

TABLE  62.    SUMMARY  OF  PRELIMINARY  STUDIES  TO  DETERMINE  THE  RELATION  BETWEEN 
SIZE  OF  THE  CHICK  AND  SIZE  OF  THE  EGG  FROM  WHICH  IT  WAS  HATCHED 


Age  of  chicks 

1911  offspring 

1912  offspring 

Coefficient 
of 
correlation 

r 
Er 

Number 
of  indi- 
viduals 

Coefficient 
of 
correlation 

r 
Er 

Number 
of  indi- 
viduals 

1  day  
4  weeks 

.844±.021 
.461  ±.060 
.311±.067 
.362db.068 
.380±.068 
.263±.073 
.308±.072 
.296±.077 
.509±.064 
.392±.074 
.S97db.079 
.458±.081 
.355±.090 
.353±.089 
.355±.089 
.306±.092 
.340±.090 
.370±.089 
.363±.089 
.224±.098 
.315±.093 
.276±.095 
.086±.103 
.549±.073 
.441±.083 
.492±.079 
.441±.084 
.356±.093 
.270±.099 
.222±.102 
.164±.104 
.337±.095 
.368±.093 

40.19 
7.68 
4.64 
5.32 
5.59 
3.60 
4.28 
3.84 
7.95 
5.30 
5.03 
5.65 
3.94 
3.97 
3.99 
3.33 
3.78 
4.16 
4.08 
2.29 
3.39 
2.91 
0.64 
7.52 
5.31 
6.23 
5.25 
3.83 
2.73 
2.18 
1.58 
3.55 
3.96 

82 
80 
82 
75 
72 
73 
73 
65 
61 
60 
51 
44 
43 
44 
44 
44 
44 
43 
43 
43 
43 
43 
43 
42 
42 
42 
42 
40 
40 
40 
40 
40 
40 

.745±.017 
.024±.050 
.074±.058 
.099±.059 
.088±.063 
.046±.069 
.301  ±.082 
.363±.076 
.401  ±.055 
.350±.058 
.420±.057 
.506±.052 
.378±.062 
.328±.066 
.310±.067 
.367±.067 
.405±.064 
.246±.071 
.331±.025 
.409±.075 

43.82 
0.48 
1.28 
1.68 
1.40 
0.67 
3.67 
4.78 
7.29 
6.03 
7.37 
9.73 
6.10 
4.97 
4.63 
5.48 
6.33 
3.46 
13.24 
5.45 

308 
179 
134 
125 
110 
96 
56 
59 
108 
104 
96 
92 
88 
83 
82 
.  80 
77 
79 
78 
56 

8  weeks  .  .  . 

12  weeks  
16  weeks  
20  weeks  

24  weeks  
28  weeks  

32  weeks  

36  weeks 

40  weeks  
44  weeks  .... 

48  weeks  
52  weeks  
56  weeks  

60  weeks 

64  weeks 

68  weeks  .... 

72  weeks  
76  weeks  
80  weeks  
84  weeks  

88  weeks  

92  weeks 

96  weeks  . 

100  weeks  .  . 

104  weeks  
108  weeks  
112  weeks  
116  weeks  

120  weeks 

124  weeks  . 

128  weeks. 

In  both  years  the  value  r  seems  to  have  been  higher  during  cold  weather, 
which  occurred,  for  the  1911  offspring,  from  the  thirtieth  to  the  forty- 
fourth  week  and  from  the  ninety-second  to  the  onerhundredth  week, 
and  for  the  1912  offspring  from  the  thirtieth  to  the  forty-fourth  week. 
This  seems  to  be  due  to  the  fact  that  the  larger,  stronger  birds  were 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   273 


able  to  withstand  the  severe  winter  weather  relatively  better  than  the 
smaller  birds  from  the  smaller  eggs. 

A  similar  tendency  may  be  noted  for  the  -j^.  to  increase    during    the 

first  winter,  in  the  curve  representing  all  birds  in  figure  43,  but  no 
definite  increase  in  this  factor  can  be  observed  for  any  of  the  later 
winters.  No  definite  tendency  can  be  seen  toward  an  increase  or  a 

decrease  in  the  factor  g;  as  the  birds  bacome  older  after  the  fourth  week. 
The  factor  j^.  at  the  one-day  age  is  very  large,  as  might  be  expected. 

From  the  fourth  week  to  the  twentieth  week  of  the  1912  offspring,  it 
will  be  noticed  that  the  coefficient  of  correlation  is  very  low.  The  only 
explanation  of  this  is  that  it  may  be  due  to  an  error  in  taking  the  weights. 
The  balance  used  was  rather  heavy,  and  the  hundredths  of  pounds  had 
to  be  estimated.  It  is  possible  that  the  flapping  and  jumping  of  the  larger, 
more  vigorous  chicks  caused  their  weight  to  be  underestimated,  thus  tend- 
ing to  reverse  the  correlation.  In  spite  of  these  few  discrepancies,  it  will  be 
noted  that  the  correlation  is  always  positive  and  in  most  cases  significant. 

The  studies  that  were  made  on  all  available  birds  during  the  entire 
experiment  are  shown  in  tables  63  to  119,  and  are  summarized  in  figure 
43  (page  271)  and  in  table  120. 

TABLE  63.     SIZE  (WEIGHT  IN  GRAMS)  OF  BIRDS  AT  AGE  OF  1  DAY,  SUBJECT;  SIZE  OF  EGGS 
FROM  WHICH  RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .73  =h  .013 
44    46    48    50    52    54    55    58    60    62    64    63    68    70 


23-25 

1 

1 

25-27 

7 

7 

14 

27-29 

8 

17 

6 

8 

1 

1 

1 

42 

29-31 

5 

15 

17 

20 

16 

6 

2 

1 

82 

31-33 

1 

3 

11 

25 

39 

21 

6 

2 

109 

33-35 

2 

1 

11 

12 

19 

26 

22 

5 

4 

102 

35-37 

1 

2 

5 

4 

14 

24 

23 

10 

1 

84 

37-39 

1 

3 

13 

6 

10 

8 

10 

7      2 

60 

39-41 

4 

3 

7 

9 

8 

7      4 

42 

41^3 

2 

3 

3 

6 

3 

441 

26 

43-45 

1 

1 

2      1 

5 

45-47 

1 

1 

47-49 

1 

1 

2 

49-51 

1      1 

2 

51  or  more 

1 

1 

I    23    45    48    74    98 


76    56    35    20    12      3      2       573 


274 


EARL  W.  BENJAMIN 


TABLE  64. 


20    30 

30-  40 

40-  50 

50-  60 

60-  70 

70-  80 

80-  90 

90-100 

100-110 

110-120 

120-130 

130-140 

140-150 

150-160 

160-170 

170-180 

180-190 

190-200 

200-210 

210-220 

220-230 

230-240 

240-250 


SIZE  OF  BIRDS  AT  AGE  OF  4  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .20  ±  .037 
44    46     48    50    52    54    56    58    60    62     64     66    68    70 


1     1 

1 
1     1 

1       1       2 
1       2       1 

2 

3 
1 

2 

1 
4 

5 
2 

1 

4 
2 
1 

1 
1 
1 
2 

1 
1 
2 

6 
1 

1 
2 

4      2 

1 

2 

1 

2 

3 

1       5      7 

7 

10 

6 

5 

4 

1 

1       1 

2       1       2 

4 

8 

5 

5 

3 

5 

2 

1 

1112 

4 

10 

9 

7 

4 

2 

3      2 

1 

1 

2 

3 

5 

5 

4 

4 

1 

1 

1 

5 

4 

5 

6 

1 

1       2 

1       2 

2 

1 

1 

3 

1 

2 

1       1 

1 

1 

1 

1 

1       1 

1 

2 

1 

1 

1 

1 

2 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1      7     19    20    36    53    44    44    33     19     10      7      2      4 


5 

3 

16 

6 

19 

11 

15 

48 

38 

47 

26 

28 

12 

6 

5 

4 

1 

3 

2 

0 

1 

1 

o 


299 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   275 


TABLE  65.     SIZE  OF  BIRDS  AT  AGE  OF  8  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .14  ±  .038 
44    46    48    50    52    54    56    58    60    62    64    66    68    70 


80-100 
100-120 
120-140 
140-160 
160-180 
180-200 
200-220 
220-240 
240-260 
260-280 
280-300 
300-320 
320-340 
340-360 
360-380 
380-400 
400-420 
420-440 
440-460 


1 

2 

1 

1 

1 

2      1 

2 

3 

2 

1 

4 

1 

2 

3 

1 

1 

1 

1 

1 

4 

3 

2 

1 

2 

2 

2 

1 

2 

5 

1 

6 

4 

1 

3 

2 

> 

1             2 

4 

4 

7 

4 

4 

2 

2 

1 

1 

3      2 

3 

3 

9 

2 

7 

4 

1 

1      2 

3 

6 

8 

7 

4 

1 

1 

1 

2 

4 

2 

5 

4 

3 

5 

2 

1 

1       1 

1 

2 

5 

1 

6 

7 

2 

1 

3 

2 

2 

1 

1 

6 

4 

3 

1 

1 

1 

1 

2 

1 

1 

2 

2 

5 

3 

1 

1 

1 

5 

3 

3 

4 

3 

3 

'  1 

1 

1 

1 

1 

1 

1 

1 

1 

2 

3 

8 

16 

19 

24 

32 

34 

33 

31 

32 

21 

16 

22 

5 

1 

1 

1 


1   7  19  22  37  53  44  44  31  19  11   7   3   4   302 


276 


EARL  W.  BENJAMIN 


TABLE  66.     SIZE  OF  BIRDS  AT  AGE  OF  12  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .20  ±  .040 


300-320 

320-340 

340-360 

360-380 

380-400 

400-420 

420-440 

440-460 

460-480 ' 

480-500 

500-520 

520-540 

540-560 

560-580 

580-600 

600-620 

620-640 

640-660 

660-680 

680-700 

700-720 

720-740 

740-760 

760-780 

780-800 


44  46  48  50  52  54  56  58  60  62  64  66  68  70 


1 
1    1 

2 

1 

1 

2 

1 

3 
3 

1 

1 

2 
1 
2 
2 

1 

1 

1 

1 

2 

2 

1 

1 

1 

3 

2 

1 

1 

1 

1 

1 

2      1 

1 

2 

2 

2 

1 

1 

2      3 

1 

6 

1 

2 

1 

1 

1              1 

1 

1 

2 

2 

3 

1 

3 

2 

2 

3 

5 

3 

1 

1 

1 

1 

1 

2 

3 

2 

4 

2 

3 

1 

1 

8 

6 

6 

1 

1 

1       1 

1 

1 

1 

3 

3 

5 

2 

2              1 

2 

5 

2 

3 

1 

2 

1 

2 

1 

5 

2 

3 

1 

1 

1      1 

1 

1 

2 

3 

4 

1 

1 

3 

2 

1 

1 

2 

1 

1 

1      2 

1 

1 

2 

2 

1 

2 

3      1 

1 

2 

1 

2 

1 

1 

1 

3 

1 

1 

1 

1 

1 

1 

6 
1 

12 

8 

6 

13 

12 

17 

12 

20 

2 

19 

25 

18 

15 

16 

14 

7 

8 

13 

6 

7 

1 

2 

2 


1   7  16  17  32  45  38  36  29  18  11   7   2   3   262 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  277 


'ABLE  67.     SIZE  OF  BIRDS  AT  AGE  OF  IG^WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .19  ±  .040 


360-  400 

400-  440 

440-  480 

480-  520 

520-  560 

560-  600 

600-  640 

640-  680 

680-  720 

720-  760 

760-  800 

800-  840 

&40-  880 

880-  920 

920-  960 

960-1000 

1000-1040 

1040-1080 

1080-1120 

1120-1160 

1160-1200 

1200-1240 

1240-1280 


44    46    48    50    52    54    56    58    60    62    64    66    68    70 


1 

1 

1 

3 

1 

1 

2 

1 

1 

3 

2 

2 

1 

1 

1 

2 

3 

3 

3 

1 

1 

1 

2 

1 

2 

1                     1 

1    1 

2 

2 

1 

4 

4 

1 

1       2       1 

1 

2 

1 

3 

1 

2 

2 

2 

2 

2 

2 

2                     1 

1      2 

1 

2 

4 

2 

3 

2 

2 

1 

3 

4 

2 

2 

1      1                     1 

1 

4 

5 

3 

3 

3 

2              1 

2 

2 

3 

5 

4 

2 

1 

1 

1      2 

4 

4 

3 

6 

9 

1 

1 

3 

7 

3 

3      2      1 

1 

1 

2 

2 

1 

2 

1 

2 

1 

1 

1 

1 

1 

1 

1 

1 

1 

34      1 

3 

2 

1      1      1 

2 

1             1 

2 

1 

1 

u-^ 

1 

I 

1 

7 

7 

6 

13 

9 

16 

12 

15 

17 

17 

22 

20 

30 

20 

9 

8 

12 

8 

4 

4 

1 

1 


1      7    16    20    30    42    41    38    25    18    11      6      2      2       259 


278 


EARL  W.  BENJAMIN 


TABLE  68.     SIZE  OP  BIRDS  AT  AGE  OF  20  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 


400-  500 

500-  600 

600-  700 

700-  800 

800-  900 

900-1000 

1000-1100 

1100-1200 

1200-1300 

1300-1400 

1400-1500 


Coefficient  of  correlation  =  .18  d=  .040 
44    46    48    50    52    54     53    58    60     62    64    63    68 


70 


1 

1 

1 

1 

3 

3 

3 

2 

1 

1 

1 

3 

3 

1 

4 

1 

2 

1       1 

7      3 

5 

4 

5 

5 

5 

6 

3 

1 

1      2 

5 

9 

13 

10 

10 

3 

5 

1 

1 

4 

5 

3 

12 

8 

5 

9 

1 

4 

2      1 

1 

2 

5 

6 

2 

8 

8 

4 

2 

3      2 

2 

2 

1 

6 

4 

4 

1 

1 

2 

1 

1 

1 

2 

5 

10 

17 

44 

60 

54 

43 

23 

2 

1 


1      8     13    24    27    40    36    39    35     11     12      9      4      2       261 


TABLE  69.     SIZE  OF  BIRDS  AT  AGE  OF  24  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .15  ±  .066 


600-  700 

700-  800 

800-  900 

900-1000 

1000-1100 

1100-1200 

1200-1300 

1300-1400 

1400-1500 

1500-1600 

1600-1700 

1700-1800 

1800-1900 


46    48  ,50    52    54    56    58    60    62    64    66    68    70 


1 

1 
1 

1 

1 

1 

3 

1 

3 

1       1 

3 

2 

2 

1 

2 

3 

1 

2 

1              1 

1 

1 

3 

4 

7 

1 

4 

1       2              1 

1 

3 

4 

4 

6 

4 

7 

1 

2 

1 

1 

4 

2 

5 

6 

2121 

1 

2 

1 

2 

2 

1      3      3 

2 

1 

2 

3 

1 

1 

4      8      9     15    20    20    20    22      5      8      6      2      1 


2 
2 
1 

10 

18 

25 

30 

27 

15 

5 

3 

1 

1 


140 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  279 

TABLE  70.     SIZE  OF  BIRDS  AT  AGE  OF  28  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .12  ±  .039 


600-  700 
700-  800 
800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1GOO-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2109 
2100-2200 
2200-2300 


44    46    48    50    52    54    56    58    60    62    64    66    68    70 


1 

1 

2 

1 

1 

2 

1 

1 

2 

4 

1 

3 

6 

2 

1 

2 

1 

1 

17 

3 

2 

6 

3 

3 

5 

2 

1 

25 

122 

4 

9 

10 

6 

10 

6 

1                      2 

53 

3 

5 

4 

6 

6 

8 

6 

1 

4121 

47 

6 

6 

5 

11 

7 

3 

6 

1 

3111 

51 

1 

1 

4 

7 

6 

6 

5 

2 

3      2      1 

38 

1 

1 

2 

5 

5 

2 

1 

3 

20 

2 

1 

1 

1 

2 

1 

3 

1 

1 

13 

1 

2 

2 

1 

2 

8 

1 

1 

2 

4 

1 

1 

2 

0 

0 

1 

1 

1      8     14    25    33    47    38    41    40    11     11      9      5      4       287 


'ABLE  71.     SIZE  OF  BIRDS  AT  AGE  OF  32  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Efficient  of  correlation  =  .31  ±  .036 


700-  800 
800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1.300 
1300-1400 
1400-1500 
1500-1600 
16001700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


44    46    48    50    52    54    56    58    eO    62    64    66    68    70 


1  1 
1 

1      121 
2      3 

1      1   7 
1126 

1 
1 
4 
6 

1 

1 
7 

1 

5 
9 

1 

2 
2 
3 

2 

2 

1   1 

1 

3375 

10 

4 

2 

10 

1 

2 

355 

11 

10 

6 

8 

1 

2 

2 

2 

444 

9 

5 

6 

3 

2 

1 

1 

1        3 

4 

8 

2 

4 

2 

2 

1   1 

1 

1      1 

2 

6 

2 

1 

2 

2 

2 

2 

1 

1 

1 

1 

1 

1 

1 

1 

1 

2 

1 

3 

1 

7 

11 

23 

38 

47 

55 

39 

29 

15 

9 

4 

1 

3 

1 


1      8    14    26    32    48 


41    38    11     11      9      5      4       286 


280 


EARL  W.  BENJAMIN 


TABLE  72.     SIZE  OF  BIRDS  AT  AGE  OF  36  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .33  ±  .037  .  .~J  ;   ] 
44    46    48    50    52    54    56    58    60    62    64    66    68 


700-  800 
800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


70 


1 

1 

2 

0 

2 

1 

3 

1 

1 

1 

1 

1 

5 

2 

1 

3 

3 

1 

3 

1 

14 

3 

6 

3 

3 

4 

7 

2 

1 

1 

30 

3 

4 

3 

7- 

7 

8 

4 

1      3 

1       1 

42 

2      5 

5 

8 

9 

6 

6 

6 

1 

48 

1      1 

5 

5 

7 

7 

4 

6 

2      3 

2       1       2 

46 

1 

1 

1 

10 

6 

7 

3 

1 

2       1       1 

34 

1 

3 

2 

4 

1 

3 

2 

16 

2 

3 

4 

4 

2 

3 

18 

1 

2 

1 

1       1 

6 

1       1 

2 

1 

1 

2 

1 

1 

13    25    28    44    38    41     33    10    11      9      5      3 


269 


TABLE  73.     SIZE  OF  BIRDS  AT  AGE  OF  40  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE   CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .28  ±  .038 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


46    48    50    52    54    56    58    60    62    64    66    68     70 


1 

1 

1 

1 

2 

2 

2 

1  1 

2 

6 

3 

2 

3 

18 

3   1 

6 

6 

9 

6 

4 

7 

1 

1 

44 

3   3 

4 

6 

10 

7 

10 

7 

3 

4   3   1 

61 

6 

8 

3 

12 

7 

10 

1 

1 

2     1   1 

52 

3 

5 

6 

6 

6 

5 

2 

1         2 

36 

2 

5 

4 

5 

3 

7 

1 

1   2 

30 

3 

2 

2 

1 

1 

1   2      1 

13 

2 

3 

1 

6 

1 

1 

0 

1 

1 

2 

1 

1 

7    13    26    32    47    33    40    36    11      9      8      3      4       2G9 


STUDY  OF  SELECTIONS  FOR  Sizu,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  281 


TABLE  74.    SIZE  OF  BIRDS  AT  AGE  OF  44  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .34  ±  .035 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 


46    48    50    52    54    55    58    60    62    64    66    68    70 


1 

1 

2 

1 

2 

1 

1 

5 

3      1 

4 

4 

3 

2 

2 

4 

1 

24 

1      3 

5 

11 

9 

3 

4 

6 

1 

43 

3      3 

8 

4 

15 

8 

8 

4 

3 

1 

1 

1 

59 

3 

4 

4 

9 

8 

9 

5 

1 

3 

1 

1      2 

50 

2 

2 

6 

5 

3 

8 

7 

1 

3 

2 

1 

40 

1 

1 

2 

8 

1 

6 

3 

1 

1      1 

25 

2 

2 

1 

1 

2 

2 

10 

1 

1 

1 

3 

0 

1 

1 

2 

7      12    25    32    46    34    36    36    11      9      7      4      4       263 


TABLE  75.    SIZE  OF  BIRDS  AT  AGE  OF  48  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .27  ±  .039 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 


46  48  50  52  54  58  58  60  62  64  66  68  70 


1 

1 

1 

1 

1 

1 

4 

1  1 

5 

2 

2 

1 

3 

1 

16 

4 

6 

2 

11 

6 

4 

5 

2 

40 

2 

5 

12 

7 

5 

9 

3 

4 

2 

1     2 

52 

2  6 

5 

6 

12 

6 

7 

7 

2 

2   1 

56 

3 

2 

2 

10 

7 

5 

9 

1 

1 

2   1 

43 

4 

1 

5 

6 

3 

1 

3     1 

24 

1 

3 

2 

1 

6 

2 

15 

1 

1 

1 

3 

2 

2 

1 

1 

2 

7  12  24  31  45  33  36  35  11   9   7   4   4   258 


282 


EARL  W.  BENJAMIN 


TABLE  76.     SIZE  OF  BIRDS  AT  AGE  OF  52  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .25  ±  .039 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 


46    48    50    52    54    58    58    60    62    64    65    68    70 


1 

1 

3 

2 

5 

1 

1 

4 

3 

1 

1 

3 

4 

1 

1 

20 

4 

2 

8 

5 

5 

7 

2 

3 

1       1 

38 

1 

4 

8 

3 

22 

8 

4 

6 

1 

1111 

61 

5 

4 

10 

11 

9 

7 

8 

2 

2111 

61 

3 

1 

2 

6 

6 

7 

4 

1 

2       1 

33 

3 

1 

3 

4 

3 

2 

1       1 

18 

2 

2 

2 

3 

4 

2      2              1 

18 

0 

0 

1 

1 

2 

1 

1 

6    13    22    32    48    34    33    34    11      9      6      3      4       258 


TABLE  77.     SIZE  OF  BIRDS  AT  AGE  OF  58  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .23  ±  .039 


700-  800 
800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 


46  48  50  52  54  56  58  60  62  64  66  68  70 


1 

1 

0 

0 

5 

1 

1 

2 

9 

2 

1 

1 

3 

6 

5 

2 

3 

1 

24 

4 

2 

6 

11 

7 

5 

4 

6 

1 

1 

1 

48 

6 

3 

4 

15 

7 

10 

5 

2 

2. 

1      2 

57 

2 

5 

10 

10 

3 

4 

9 

1 

1   1 

46 

1 

•  1 

1 

8 

7 

9 

4 

1 

2 

1   1 

3G 

1 

2 

7 

2 

1 

1 

2 

1 

17 

1 

2 

3 

2 

2 

2      1 

13 

1 

3 

4 

0 

0 

1 

1 

1 

3 

6  13  22  32  48  34  86  34  11   9   6   3   4 


258 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   283 

TABLE  78.     SIZE  OF  BIRDS  AT  AGE  OP  30  WEEKS,  SUBJECT;  SIZE  OP  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCEHD,  RELATIVE 

Coefficient  of  cor  relation  =  .37  .it  .037 
45    48    50    52    54    56    53    60    62    61    65    63    70 


700-  800 
800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600- 
1303-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


1 

1 

1 

1 

2 

1 

3 

6 

1 

1 

8 

3      2 

3 

5 

3 

1 

2 

4 

2 

25 

2       1 

3 

7 

8 

2 

5 

3 

1 

32 

1       2 

4 

5 

13 

9 

4 

5 

1      2      2 

48 

5 

3 

5 

6 

8 

9 

8 

3                     1 

48 

1 

2 

5 

9 

2 

6 

5 

3                     2 

35 

2 

1 

5 

7 

6 

3 

1      1 

26 

2 

3 

3 

1 

212              1 

15 

1 

1 

1 

2      3      1 

9 

1 

1 

1 

1 

0 

1 

1 

6     13    22    32    47    34    36    32     11      9      6      2      4       234 


ABLE  79.     SIZE  OF  BIRDS  AT  AGE  OF  64  WEEKS,  SUBJECT;  SIZE  OP  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .40  =fc  .036 
43    48    50    52    54    56    53    60    62    64    66    68    70 


800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 


1 

1 

2 

1 

1 

2 

3 

2 

5 

1     1 

3 

2 

5 

1 

1 

3 

1 

18 

4      3 

3 

8 

9 

7 

3 

4 

1       1                      1 

44 

1      2 

6 

6 

13 

8 

10 

7 

2      4                     1 

60 

5 

3 

5 

9 

6 

6 

4 

2121 

44 

2 

1 

3 

4 

6 

7 

5 

1      1 

30 

3 

4 

3 

5 

4 

122 

24 

2 

2 

2 

2 

1 

9 

1 

2 

3      3 

9 

0 

1 

1 

1 

3 

1 

1 

6     13    20    31    47    34    36    32     11      9      6      2      4      251 


284 


EARL  W.  BENJAMIN 


TABLE  80.     SIZE  OF  BIRDS  AT  AGE  OF  68  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH) 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .30  ±  .039 
46    48    50    52    54    56    58    60    62    64    66    68    70 


800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


1 

1 

2 

2 

4 

1 

1 

1 

2 

9 

2 

2 

3 

2 

2 

2 

4 

1 

1 

19 

3 

1 

5 

5 

12 

3 

4 

4 

1 

38 

1 

1 

3 

8 

9 

6 

3 

3 

3 

2                     1 

40 

2 

4 

7 

4 

7 

6 

3 

1 

3211 

41 

4 

1 

5 

9 

4 

5 

6 

3 

1              1 

39 

2 

2 

6 

8 

8 

4 

1      1              1 

33 

1 

2 

4 

4 

1 

1      2 

15 

1 

1 

2 

1 

1 

1 

1 

1 

1 

1 

7 

0 

0 

1 

1 

1 

1 

6    13    21     31    47    33    36    30    11      8 


2      4       248 


TABLE  81.     SIZE  OF  BIRDS  AT  AGE  OF  72  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERS  HATCHED,  RELATIVE 

'Coefficient  of  correlation  =  .29  ±  .040 


800-  900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 


46    48    50    52_54    55    58    60    62    64    66    68    70 


1 

1 

1 

1 

2 

2 

1 

3 

3 

6 

4 

1 

2 

16 

1 

1 

3 

1 

6 

2 

4 

1 

1 

1 

21 

2 

2 

6 

5 

7 

7 

7 

4 

2 

1112 

47 

3 

4 

8 

9 

7 

6 

4 

2      1 

44 

3 

6 

8 

3 

7 

10 

4 

3              1 

45 

2 

4 

6 

6 

4 

2 

1 

2      1              2 

30 

1 

4 

2 

4 

3 

6 

1 

21 

1 

2 

2 

2 

1 

8 

1 

1 

2 

1 

1 

1 

1 

0 

0 

1 

1 

2 

6    13    20    30    46    33    34    30    11      9      6      2      4       244 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   285 

TABLE  82.    SIZE  OF  BIRDS  AT  AGE  OF  76  WEEKS,  SUBJECT;  SIZE  OF  EGOS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .26  =b  .043 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 
2600-2700 


46    48    50    52    54    56    58    60    62    64    66    68    70 


1 

* 

1 

2 

2 

1 

1 

4 

1 

1 

1 

3 

1 

4 

5 

2 

2 

1 

1      1 

17 

3      2 

5 

3 

10 

6 

5 

3      1 

1                     1 

40 

2      4 

3 

8 

4 

4 

10 

7 

1      2 

45 

2 

4 

4 

7 

6 

4      1 

2              1 

31 

1 

2 

3 

6 

3 

3 

4      3 

2                     1 

28 

1 

'  5 

3 

5 

2 

2      1 

2      1              1 

23 

2 

3 

1 

2 

4 

1 

13 

1 

3 

2 

1 

7 

1 

1 

2 

2 

2 

4 

1 

1 

1 

1 

2 

0 

0 

1 

1 

6     11     17    2J    40    32    33    28     10      9      6      2      3        223 


TABLE  83.    SIZE  OF  BIRDS  AT  AGE  OF  80  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FRDM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .24  ±  .048 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 


46    48    50    52    54    56    58    60    62    64    66    68"  70 


1 

1 

1      2 

3 

1 

2 

1 

4 

1             4 

2 

2 

2 

1 

1 

1              1 

15 

2             2 

3 

9 

2 

7 

6 

1 

1              1      1 

35 

1      2      1 

4 

4 

5 

5 

5 

1 

28 

1      1 

2 

2 

5 

4 

2 

1 

1 

19 

2 

2 

5 

1 

4 

2 

3 

1 

20 

1 

5 

4 

5 

2 

21              1 

21 

1 

2 

1 

2 

4 

3              1 

14 

1 

3 

1 

1 

6 

2 

2 

1 

5 

2 

2 

4 

1    i 

1 

1 

1 

0 

1 

1 

5      6    12    20    32    24    27    24    10      8      5      2      3        178 


286 


EARL  W.  BENJAMIN 


TABLE  84.     SIZE  OF  BIRDS  AT  AGE  OF  84  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .33  db  .054 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 


46    48    50    52    54    56    58    60    62    64    66    68    70 


1 

2 

3 

1 

1 

1 

3 

1 

2 

1       1                      1 

233 

3 

4 

3 

1 

2 

1       1      2 

4 

5 

1 

4       1              1 

1              2 

1 

3 

1 

3       1                      1 

2 

3 

2 

2 

3      1      3 

1              2 

3 

1 

2 

21                     1 

3 

5 

1 

2       1       2 

1 

1 

1 

1              1 

1 

1 

1 

1 

1 

3      5      7     13    24    22     15     17      7      6      3      2      1 


1 

0 

2 

4 

11 

19 

22 

13 

16 

13 

14 

5 

2 

1 

0 

2 

125 


TABLE  85.     SIZE  OF  BIRDS  AT  AGE  OF  88  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .30  d=  .057 
46    48    50    52    54    56    58    60    62    64    66    68    70 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 
2600-2700 


1 

1 

0 

1 

1 

1 

1 

2 

2      1 

1 

1 

5 

1 

2 

2 

3 

1              1       1 

11 

1324 

3 

6 

1 

2 

1              1 

24 

3      1 

3 

3 

3 

2 

1       1 

17 

1             3 

2 

2 

2 

3 

1      2 

16 

4 

5 

2 

11 

1 

1 

1 

3 

2 

1 

9 

1              1 

3 

1 

1 

2       1       1 

11 

1 

1 

1 

2      1 

4 

0 

1 

1 

0 

1 

1 

2      5      8     12    20     19     14     16      8      5      4 


1        115 


ITUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   287 


TABLE  86.    SIZE  OF  BIRDS  AT  AGE  OF  92  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .30  ±  .055 
46    48    50    52    54    56    58    60    62    64    66    68    70 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 


1 

1 

2 

2 

1 

2 

1 

6 

1      1      1 

1 

5 

2 

2 

1 

1 

15 

1      2 

3 

7 

4 

3 

5 

1 

26 

1      1 

2 

2 

3 

1 

2      2 

14 

1             2 

3 

4 

4 

2 

3 

1      2      1 

23 

1 

3 

2 

2 

1 

1 

10 

1 

2 

2 

1 

1  • 

1                            1 

9 

1 

3 

1 

2 

1 

8 

1 

1      1      1 

4 

1 

1              1 

3 

0 

1 

1 

2 

1 

1 

3      5      7    12    23    20    15    17      8      6      4      2      1       123 


TABLE  87.     SIZE  OF  BIRDS  AT  AGE  OF  96  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .40  ±  .051 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


46    48    50    52    54    58    58    60    62    64    66    68    70 


1 

1 
1    1 

1 

1      3      3 
246 

2 
4 

2 

2 
3 

2 

1      2 

1      2      5 

3 

4 

4 

1 

1      3      3 

3 

2 

4 

2 

3 

1      1 

3 

5 

1 

1 

1 

3 

4 

2 

2 

1 

1 

1 

1 

1 

2 

1 

1 

2 

1 

1 

1 

1 

356    12    2320    15    17      86421 


1 
1 

14 

23 

23 

23 

"11 

7 

7 

5 

3 

1 

3 

122 


288 


EARL  W.  BENJAMIN 


TABLE  88.    SIZE  OF  BIRDS  AT  AGE  OF  100  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .35  ±  .055 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 


46    48    50    52    54    56    58    60    62    64    66    68    70 


1     1 

1              2      1 

1 

1 

2 

1                     2 

3 

1 

1 

3 

1 

1313 

7 

5 

2 

1 

2                      1 

1       1      2 

3 

2 

5 

3 

1      2      1 

1 

3 

1 

2 

3 

2 

2 

3 

3 

2 

3 

2 

2 

1 

2 

1 

1 

1 

1 

1              1 

t 

1 

1      2 

1 

1 

1 

1 

2 

8 

12 

26 

21 

12 

13 

8 

5 

4 

2 

1 

0 

1 


3      5      6    11    22    17    15    15      8      6      4      2      1        115 


TABLE  89.     SIZE  OF  BIRDS  AT  AGE  OF  10 1  WEEKS,  SUBJECT;  SIZE  OF  EGG3  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .32  ±  .057 
46    48    50    52    54    56    58    60    62    64    66    68    70 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


1 

1 

1         1     1 

1 

4 

1 

3 

2 

1 

3 

1 

11 

1    1     1 

5 

1 

2 

1 

12 

1214 

3 

5 

2 

1 

1              1       1 

22 

1                     2 

3 

1 

2 

5 

1      1 

16 

1       1      2 

2 

1 

2 

3 

2      1       1 

16 

1 

4 

4 

3 

1 

2      1 

16 

1 

1 

1 

3 

1 

1 

1                            1 

4 

1 

2 

1 

4 

2 

2 

1 

1 

2 

3      5      6    11    21     17    14    15      8      6      4      2      1       113 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   289 


TABLE  90.    SIZE  OF  BIRDS  AT  AGE  OF  108  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FBOM  WHICH 
RESPECTIVE  CHICKS  WEBB  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .34  =b  .056 
46    48    50    52    54    56    58    60    62    64    66    68    70 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


1 
i          2 

1      2 

1                     2      7 

2 
3 

1 

1 
1 
1 
3 

1 
1 

2224 

3 

2 

1 

1 

12141 

1 

3 

3 

2 

1      1 

2      4 

2 

2 

2 

1       1 

2 

1 

4 

1 

1 

2 

1      1 

1 

3 

1 

2 

1 

1 

1 

1 

2 

1 

1 

1 

1 

1 

3      5      6    11    21     17     14    15 


642 


2 

4 

7 

18 

17 

20 

14 

13 

9 

4 

1 

3 

0 

1 

113 


TABLE  91.    SIZE  OF  BIRDS  AT  AGE  OF  112  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .25  ±  .060 


900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


46    48    50    52    54    53    58    60    62    64    65    68    70 


1 
1 

1    1    1 

1      3   5 

5 

1 

1 
3   1 
1   1         1 

12246 

1 

2 

3   1   2 

11112 

3 

3 

4      121 

1   3 

1 

3 

1      11      1 

2   4 

3 

1 

1 

2 

3 

1   2   2 

1 

1 

1   1 

1      1 

1 

1 
1 
1 

7 

18 

24 

20 

12 

11 

10 

4 

0 

2 

0 

1 


3      5      6    11    21     16    14    15      8      6      4      2       1      112 


290 


EARL  W.  BENJAMIN 


TABLE  92.     SIZE  OP  BIRDS  AT  AGE  OF  116  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .28  ±  .059 
46    48    50    52    54    56    58    60    62    64    66    68    70 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 


1 

1 

2 

1    1    1 

1 

4 

1 

1 

2 

4 

1                     2 

3 

3 

2 

2 

1              1      1 

16 

1      3      1 

3 

1 

3 

2 

14 

2113 

9 

3 

3 

2 

2 

23 

1             2 

2 

1 

4 

2 

2      1 

15 

1 

3 

1 

1 

1              1 

8 

1 

2 

2 

1 

1              1              1 

9 

1 

1 

2 

3 

2      1 

10 

0 

1 

1 

2 

0 

1 

1 

1 

1 

3      5 


11    21     15     14     15 


6421 


112 


TABLE  93.     SIZE  OF  BIRDS  AT  AGB  OF  120  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .29  ±  .059 
46    48    50    52    54    53    58    60    62    64    63    68    70 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


1      2 

1 

1      3              1 

1 

1 

1 
1 

1      2 
1                     3 

2 

2 

3 
1 

2 

{       i 

1 

2249 

5 

2 

4 

1 

3      4 

1 

2 

5 

1 

2      1      1 

1 

1 

2 

1              1 

1 

2 

2 

1 

1 

1 

3 

1 

1 

1 

1 

1 

1 

1 

1 

3      5      6    10    21     15     13    14      8      6      4      2      1 


1 

3 

7 

8 

14 

30 

20 

6 

6 

6 

3 

1 

2 

1 

108 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  291 


TABLE  94.     SIZE  OF  BIRDS  AT  AGE  OF  124  WEEKS,  SUBJECT;  SIZE  OF  EGOS  FBOM  WHICH 
RESPECTIVE  CHICKS  WEBB  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .41  ±  .054 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1300-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


46    48    50    52    54    53    58    60    62    G4    66    68    70 


2 

, 

3 

2 

1 

1 

4 

232 

1 

1 

1 

1 

1 

12 

1      1 

1 

5 

1 

5      1 

1 

16 

1 

2 

6 

3 

1 

2      1 

2              1 

19 

1 

5 

2 

6 

4 

4 

2              1 

25 

3 

3 

3 

1 

2              1 

13 

1 

1 

2 

2      1 

1 

8 

1 

1 

1       1 

4 

1 

1 

1 

1 

2 

2 

2 

3      5      6    10    21     15    13     15      8      6      4      2      1 


109 


TABLE  95.     SIZE  OF  BIRDS  AT  AGE  OF  128  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .33  db  .069 
45    47    49    51    53    55    57    59    61     63    65    67 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


1              1      2      2 

1 

2             3 

2 

1              1 

3122 

1 

4 

2 

1 

1                     1      1 

3 

2 

1 

1                     1 

1              3 

3 

1 

2             1 

1 

3 

2 

1 

1                     1 

2 

1 

1              1 

1 

1 

1      1 

1 

1 

1 

2455    13      9    12      9744 


7 

9 

16 

11 

11 

6 

1 

7 

4 

2 

1 

75 


292 


EARL  W.  BENJAMIN 


TABLE  96.     SIZE  OF  BIRDS  AT  AGE  OF  132  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .42  ±  .074 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


45    47    49    51    53    55    57    59    61     63    65 


1 

1      2 
2      1              2 

1      1 

1 

1      1 

1 

1 

1                            2 

3 

2      3 

2 

1 

1             3 

1      2 

1 

4 

1 

1 

1 

1       1 

1 

1 

1 

2 

1 

1 

1 

1 

1432    11      797444 


1 
4 

-7 
4 
11 
7 
9 
4 
2 
4 
2 
0 
1 


56 


TABLE  97.     SIZE  OF  BIRDS  AT  AGE  OF  136  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .44  ±  .077 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


45    47    49    51    53    55    57    59    61     63    65 


"  ] 

1    1    ] 
1     1     ] 

[ 

[ 
[  ' 
1    1 

1 

1 

1 
1              1 

1 

] 

L             4 

1 

1 

1 

1      1 

1 

2      2 

1 

1 

1 

1 

1 

1              1 

1 

2 

1              2 

1 

1 

1 

1 

1 

1 

1 

1 

24428677344 


51 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  293 


TABLE  98.    SIZE  OF  BIRDS  AT  AGE  OF  140  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FBOM  WHICH 
RESPECTIVE  CHICKS  WEBB  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .41  ±  .071 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 


45    47    49    51    53    55    57    59    61    63    65 


1 

1 

1 

2             2 

1 

1 

2      2                            1 

2 

1 

2 

2 

1 

1              161 

3 

1 

1      1      3 

1 

1 

'    1 

1                            1 

3 

1 

2 

1 

2 

1 

1 

1 

1 

1       1 

1 

1 

2443    11      6    11      8544 


1 
0 
2 
6 
7 
6 
13 
8 
6 
5 
2 
4 
0 
1 
1 


62 


TABLE  99.    SIZE  OF  BIRDS  AT  AGE  OF  144  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FBOM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .44  ±  .074 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2oOO 
2500-2600 


45    47    49    51    53 .  55    57    59    61    63    65 


1 

1     1 

1 

1 

1 

1 

221              2 

2      2 

1 

12             11 

2 

2      1      1 

2 

3      1 

1 

1      1 

1 

2      1 

1 

1 

1 

1 

1 

2343    10      4     11      8324 


1 
3 

1 
2 
12 
7 
7 
6 
4 
4 
3 
2 
1 
0 
1 

54 


294 


EARL  W.  BENJAMIN 


TABLE  100.    SIZE  OF  BIRDS  AT  AGE  OF  148  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WEKE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .49  ±  .070 
45    47    49    51    53    55    57    59    61    63    65  , 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 
2600-2700 
2700-2800 


2 

1 

1       1 

21                     2 

2 

2 

1      3      4 

1      3 

1 

1 

2      1              1 

1 

2 

1 

1 

2 

3       1 

2 

1 

1 

1 

1      1 

1 

1 

1 

1 

2      3      4      3    10      4    11 


324 


2 
3 
9 
14 
5 
4 
6 
4 
4 
1 
1 
0 
0 
0 
0 
1 

54 


TABLE  101.     SIZE  OF  BIRDS  AT  AGE  OF  152  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE   CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .52  ±  .068 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
16PO-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


45    47    49    51    53    55    57    59    61    63    65 


1 

2 

1 

1 

1 

4      1       1 

1       1 

2 

112             2 

2 

1 

11314 

1 

2 

2 

2      1 

1      1 

2 

1 

1 

1 

1 

1 

33394    11      83 


1 
4 
9 
11 
13 
2 
5 
3 
1 
2 
1 


52 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE-,. A&i  COLOR" ok IJiiis!  .feas  295 


TABLE  102.     SIZE  OF  BIRDS  AT  AGE  OP  156  WEEKS,  SUBJECT;  SIZE  OF  EGOS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .50  =t  .078 
45    47    49    51    53    55    57    59    61    63    65 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 


1 

1     1 

21111 

1                     3111 

2              1              122 

2 

1      1                     3 

1 

2              1       1 

1              1       1 

1 

1 

1 

233373 


5323 


1 
2 
8 
7 
10 
6 
4 
3 
1 
1 
1 


42 


TABLE  103.     SIZE  OF  BIRDS  AT  AGE  OF  160  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .48  ±  .072 
45    47    49    51    53    55    57    59    61     63    65 


1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


1 
1     1 

1     1     1 

1              3 

1 

1      1 

1 

1      2 

2 

3 

1 

1      1       1 

1      3 

4 

1 

1      3 

1 

1 

1 

%    ;- 

1 

2 

1 

1 

1 

1 

1 

1 

1 

233394    11      8324 


5 

8 
9 
12 
5 
3 
4 
3 
0 
3 


52 


296 


W.  BENJAMIN 


TABLE  104.     SIZE  OF  BIRDS  AT  AGE  OF  164  WEEKS,  SUBJECT;  SIZE  OF  EGOS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .43  ±  .078 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 


45    47    49    51     53    55    57    59    61     63    65 


1 

1 

1 

1 

1 

1 

1              1 

2 

1 

2              1      2 

1      1 

1 

2      1      1 

1      3 

2 

1 

2 

2 

1 

1 

2      1 

2 

2      1 

1 

1 

1 

1 

1 

1 

2      3      3      2      8      4    11 


324 


1 
4 
6 
8 
11 
5 
4 
6 
1 
2 
1 
0 
0 
1 

50 


TABLE  105.     SIZE  OF  BIRDS  AT  AGE  OF  168  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .50  ±  .072 
45    47    49    51    53    55    57    59    61     63    65 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


1 

1 

111             2 

1 

2      1 

1 

2             23 

1 

1 

1 

2 

2 

2 

1 

3      3 

1 

1 

3 

2 

1 

1 

1 

1 

1 

1 

1 

233284    11      7324 


1 
0 
1 

10 
10 
6 
8 
6 
3 
1 
1 
2 

49 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   297 


TABLE  103.    SIZE  OF  BIRDS  AT  AGE  OP  172  WEEKS,  SUBJECT;  SIZE  OF  Eoos  FBOM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .52  rh  .070 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 


45    47    49    51    53    55    57    59    61    63    65 


1         1 

2                     1      1 

1 

1 

2                     3 

1 

1 

1112 

2 

2 

1 

.1 

1 

1 

2      3 

2 

1      1 

1 

2 

2 

4 

1 

1 

1 

1 

233284    11      8324 


2 
6 
7 

10 
2 

10 
5 
5 
1 
0 
1 
1 

50 


TABLE  107.     SIZE  OF  BIRDS  AT  AGE  OF  176  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .44  ±  .082 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 


45    47    49    51    53    55    57    59    61    63    65 


1    1 

*  . 

1 

1 

1    1 

2 

1 

2      1              1 

1 

1 

1 

1      2 

2 

1              1 

1 

2 

1 

1             2 

1 

2 

1       1 

1 

2 

2       1 

1 

1 

1 

23326488224 


44 


298 


EARL  W.  BENJAMIN 


TABLE  108.    SIZE  OF  BIRDS  AT  AGE  OP  180  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FBOM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .37  ±  .108 


1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 


45    47    49    51    53    55    57    59    61    83    65 


1 

1 

1 

2      2 

1 

1 

1 

1 

1 

1 

1 

1 

1      1 

1 

1 

1 

1 

2 

1 

1       1 

2 

1 

22324155023 


20 


TABLE  109.     SIZE  OF  BIRDS  AT  AGE  OF  184  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .52  =fc  .085 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800- 1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


45    47    49    51    53    55    57 


61     63    65 


1 

1                1 

1     1 

1 

1                                  2 

1             1             1 

3 

1      1 

1      3      1 

1              3 

1 

1      1 

1 

1 

1 

1 

1 

22225287022 


1 
0 
2 
3 
3 
8 
5 
5 
3 
1 
2 
1 

34 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   299 


TABLE  110.     SIZE  OF  BIRDS  AT  AGE  OF  188  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .60  ±  .099 
45    47    49    51     53    55    57    59 


1300-1400 

1         1 

2 

1400-1500 

0 

1500-1600 

1 

1 

1600-1700 

1   1 

2 

1700-1800 

1 

2 

1800-1900 

1      2 

4 

1900-2000 

1 

2000-2100 

1 

2 

2100-2200 

1      1 

2 

2200-2300 

1 

2 

2300-2400 

1 

12265 


19 


TABLE  111.     SIZE  OF  BIRDS  AT  AGE  OF  192  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .59  ±  .079 
45    47    49    51    53    55    57    59    61    63 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 


1 

2 

1 
1 

2 

2 

3 

1 

3 

1 

1 

1      1 

1 

1 

1 

1 

1 

1 

2 

1 

1 

1 

2222528701 


1 
0 

2 
1 
3 
5 
6 
3 

a 

4 
1 
1 
1 

31 


300 


EARL  W.  BENJAMIN 


TABLE  112.    SIZE  OF  BIRDS  AT  AGE  OP  196  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .48  ±  .093 


45  47  49  51  53  55 

57 

59  61  63 

1200-1300 

1 

1 

1300-1400 

0 

1400-1500 

1 

1 

2 

1500-1600 

2   1         2 

5 

1600-1700 

1         1 

1 

3 

1700-1800 

1   1 

2 

1 

5 

1800-1900 

1      1 

1 

3 

1900-2000 

1      2 

2 

1 

6 

2000-2100 

1 

2 

3 

2100-2200 

1 

1 

2 

2200-2300 

0 

2300-2400 

0 

2400-2500 

0 

2500-2600 

0 

2600-2700 

1 

1 

222252 


7      0      1 


31 


TABLE  113. 


SIZE  OF  BIRDS  AT  AGE  OF  200  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 


Coefficient  of  correlation  =  .56  db  .084 
45    47    49    51    53    55    57    59    61 


63 


1000-1100 

1 

1 

1100-1200 

0 

1200-1300 

0 

1300-1400 

1 

1 

1400-1500 

1                                    1 

2 

1500-1600 

1              1      2 

4 

1600-1700 

1              1              1              13 

7 

1700-1800 

1 

1 

1800-1900 

1              2      2 

5 

1900-2000 

1             211 

5 

2000-2100 

1 

1 

2100-2200 

1 

1 

2200-2300 

1 

1 

2300-2400 

1 

1 

2222527701 


30 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  301 


TABLE  114.    SIZE  OF  BIRDS  AT  AGE  OP  204  WEEKS,  SUBJECT;  SIZE  OP  EGGS  PBOM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 


Coefficient  of  correlation  =  .66  ±  .068 


45    47    49    51    53    55    57 


61    63 


TABLE  115. 


1100-1200 

1 

1 

1200-1300 

0 

1300-1400 

1      1 

2 

1400-1500 

1 

1 

1500-1600 

11             2 

1 

5 

1600-1700 

2      2      1 

2 

2 

9 

1700-1800 

2 

1 

3 

1800-1900 

2 

2 

1900-2000 

1 

3 

4 

2000-2100 

1 

1 

2 

2100-2200 

1 

1 

2200-2300 

1 

1 

.222252 

8 

701         31 

.    SIZE  OP  BIRDS  AT  AGE  OP  208  WEEKS, 

SUBJECT;  SIZE  OP  EGOS  FROM  WHICH 

RESPECTIVE  CHICKS  WERE  HATCHED 

,  RELATIVE 

Coefficient  of  correlation  = 

.49  ±  .092 

45    47    49    51    53    55 

57 

59    61    63 

1100-1200 

1 

1 

1200-1300 

1 

1 

1300-1400 

0 

1400-1500 

0 

1500-1600 

1      2      1 

1 

5 

1600-1700 

2                    2 

2 

3 

9 

1700-1800 

1                                   1 

2 

1 

5 

1800-1900 

1 

1 

2 

1900-2000 

1      1 

2 

2              1 

7 

2000-2100 

0 

2100-2200 

0 

2200-2300 

0 

2300-2400 

0 

2400-2500 

1 

1 

2222528701 


31 


302 


EARL  W.  BENJAMIN 


TABLE  116.     SIZE  OF  BIRDS  AT  AGE  OF  212  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .68  ±  .085 

45    47    49    51    53    55    57    59    61     63 


1100-1200 

1 

1 

1200-1300 

0 

1300-1400 

1 

1 

1400-1500 

1      2 

3 

1500-1600 

1      1      1 

3 

1600-1700 

123              13 

10 

1700-1800 

1                     1 

2 

1800-1900 

1      2 

3 

1900-2000 

2      2 

4 

2000-2100 

1      1              1 

3 

2100-2200 

0 

2200-2300 

0 

2300-2400 

0 

2400-2500 

1 

1 

222252 


7      0 


31 


TABLE  117.     SIZE  OF  BIRDS  AT  AGE  OF  216  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .66  ±  .070 
45    47    49    51    53    55    57    59    61     63 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 


1 

1 

1     1                1 

3 

1              111 

4 

1             1         1 

3 

1    1        1 

2 

5 

1                   1 

2                          4 

1     1 

3 

2 

1 

3 

1 

1 

2 

1 

1 

1 

1 

222242 


7      0      1 


30 


STUDY  OF  SELECTIONS  FOR  SIZE, .SHAPE,  AND  COLOR  OF  HENS'  EGGS  303 


TABLE  118.     SIZE  OF  BIRDS  AT  AGE  OF  2?0  WEEKS,  SUBJECT;  SIZE  OF  EGOS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .69  ±  .034 
45    47    49    51    53    55    57    59    61    63 


1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 


1 

2      1 

1              111 

1              1 

1 

2             2 

1 

1                     1 

3 

1                            1 

1 

1      3 

1 

1 

2222428701 


1 
3 
4 
3 
5 
5 
3 
5 
0 
1 

30 


TABLE  119.     SIZE  OF  BIRDS  AT  AGE  OF  224  WEEKS,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH 
RESPECTIVE  CHICKS  WERE  HATCHED,  RELATIVE 

Coefficient  of  correlation  =  .40  ±  .103 


1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 


45    47    49    51    53    55    57    59    61    63 


1 

1 

xl 

1 

2 

1 

1 

1 

1 

1     1 

1     1 

2 

1 

2 

1 

1 

1 

1 

1 

1       1 

1 

1 

1 

1 

222242 


7      0       1 


1 
1 
2 
5 

7 
4 
3 
4 
2 
1 

30 


304 


EARL  W.  BENJAMIN 


TABLE  120.  SUMMARY  OF  TABLES  63  TO  119.  SIZE  OF  BIRDS  AT  FOUR-WEEKS  PERIODS 
DURING  THEIR  LIFE,  SUBJECT;  SIZE  OF  EGGS  FROM  WHICH  RESPECTIVE  CHICKS  WERE 
HATCHED,  RELATIVE 


Age  of  chicks 

Coefficient 
of 
correlation 

r 
Er 

Number 
of  indi- 
viduals 

1  day                     

.73±.013 

56.15 

573 

4  weeks 

20±  037 

5  41 

299 

8  weeks 

14±  038 

3  68 

302 

12  weeks 

20±  040 

5  00 

262 

16  weeks                                                            

19±  040 

4  75 

259 

20  weeks                                        

.18±.040 

4  50 

261 

24  weeks                       

.15±.066 

2  27 

140 

28  weeks  

.12±.039 

3  08 

287 

32  weeks       

.31±.036 

8  61 

286 

36  weeks  *  

.33±.037 

8.92 

269 

40  weeks 

28±  038 

7  37 

269 

44  weeks 

34  ±  035 

9  71 

263 

48  weeks                                                

27  ±  039 

6  92 

258 

52  weeks                                                

25±  039 

6  41 

258 

56  weeks.         .  .         

28±  039 

7  18 

258 

60  weeks           

.37±.037 

10  00 

254 

64  weeks     

.40±.036 

11  11 

251 

68  weeks     

.30+.  039 

7  69 

248 

72  weeks 

29  ±  040 

7  25 

244 

76  weeks 

23±  043 

6  05 

223 

80  weeks                                                        .... 

24db  048 

5  00 

178 

84  weeks                      .  .                 ... 

.33±  054 

6  11 

125 

88  weeks           

.30±  057 

5  26 

115 

92  weeks         

.30±  055 

5  45 

123 

96  weeks 

40±  051 

7  84 

122 

100  weeks 

35  -t  055 

6  36 

115 

104  weeks 

32db  057 

5  61 

113 

108  weeks 

34±  056 

6  07 

113 

112  weeks 

25  ±  060 

4  17 

112 

116  weeks                           .              

28±  059 

4  75 

112 

120  weeks                      

.29±  059 

4  92 

108 

124  weeks         

.41=b.054 

7  59 

109 

128  weeks 

33  -t  069 

4  78 

75 

132  weeks 

42  ±  074 

5  68 

56 

136  weeks 

44±  077 

5  71 

51 

140  weeks 

41±  071 

5  77 

62 

144  weeks                                              

44±  074 

5  95 

54 

148  weeks  

49±  070 

7  00 

54 

152  weeks  
156  weeks  

.52±.068 
.50±  078 

7.65 
6  41 

52 
42 

160  weeks  

.48±  072 

6  67 

52 

164  weeks 

43  ±  078 

5  51 

50 

168  weeks 

50±  072 

6  94 

49 

172  weeks 

52±  070 

7  43 

50 

176  weeks.. 

.44+.  082 

5.37 

44 

STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS   305 

TABLE  120  (concluded) 


Age  of  chicks 

Coefficient 
of 
correlation 

r 
Er 

Number 
of  indi- 
viduals 

180  weeks  

.37±.108 

3  43 

29 

184  weeks 

52=b  085 

6  12 

34 

188  weeks 

60±  099 

6  06 

19 

192  weeks  
196  weeks  
200  weeks  

.59±.079 
.48±.093 
.56±.084 

7.47 
5.16 
6.67 

31 
31 
30 

204  weeks 

66±  068 

9  71 

31 

208  weeks 

49±  092 

5  33 

31 

212  weeks 

68±  065 

10  46 

31 

216  weeks       

66±  070 

9  43 

30 

220  weeks  

69±  064 

10  78 

30 

224  weeks  

40±  .  103 

3  88 

30 

DISCUSSION  OF  RESULTS 

The  results  of  these  studies  are  neither  in  entire  accord  nor  in  entire 
discord  with  any  of  the  important  studies  of  the  same  factors  made  by 
other  workers.  Up  to  the  present  time  no  extensive  work  has  been 
reported  on  Single  Comb  White  Leghorn  material.  So  far  as  is  known 
by  the  writer,  no  other  study  of  these  particular  factors  has  been  made 
with  similar  lines  of  inheritance  over  as  long  a  period  as  is  here  reported. 

The  studies  have  been  made  with  vitally  important  commercial  factors 
in  a  commercial  breed.  It  is  especially  incumbent  on  the  eastern  pro- 
ducer to  excel  in  the  production  of  these  desired  factors  in  order  to  compete 
with  more  distant  production.  Therefore  the  fact  indicated  by  these 
studies,  namely,  that  the  characters  in  question  are  distinctly  inherited, 
should  be  gratifying  and  encouraging  to  commercial  poultrymen  who 
have  been  working  for  years  along  these  lines. 

The  inheritance  of  the  characters  studied  seemed  to  be  thru  the  medium 
of  both  the  male  and  the  female  parent.  The  writer  found  no  evidence 
of  distinctly  sex-linked  factors,  such  as  were  observed  by  Pearl  (1912) 
and  by  Hadley  (1913).  According  to  the  writer's  results,  benefit  to  the 
flock  can  be  gained  for  any  of  these  inherited  characters  by  adding  either 
better  males  or  better  females  to  the  flock. 

The  relation  of  an  individual  egg  to  the  mean  type  produced  by  the 
parent  bird,  and  the  relation  of  the  type  of  egg  incubated  to  the  mean 


306  EARL  W.  BENJAMIN 

type  produced  by  the  progeny,  point  directly  to  an  easy  way  of  improving 
a  commercial  flock  by  careful  selection  of  the  eggs  for  hatching.  The 
results  of  this  investigation  show  that  a  study  of  all  the  eggs  produced 
by  the  parent  hen,  such  as  would  be  possible  only  by  trap-nesting,  would 
be  more  dependable  than  a  selection  of  the  incubated  eggs  alone;  but  the 
latter  method  is  found  to  be  a  possible  way,  as  well  as  an  easier  and  quicker 
way,  of  obtaining  good  results. 

The  fact  that  the  size,  the  shape,  or  the  color  of  eggs  doe's  not  affect  their 
incubation  record,  leaves  the  poultryman  free  to  select  his  eggs  for  hatch- 
ing according  to  his  own  preference  without  its.  affecting  the  percentage 
of  hatch. 

The  old  opinion  that  hens'  eggs  approach  a  definite  standard,  to  which 
they  adhere  more  uniformly  as  the  bird  becomes  older,  is  not  borne  out 
by  the  results  of  those  studies.  From  this  work  it  seems  that  the  variability 
of  a  hen's  production  does  not  decrease  as  the  hen  becomes  older.  If 
the  indication  shown  here  is  a  fact,  it  does  away  with  one  of  the  several 
arguments  which  the  poultryman  has  for  using  hens'  eggs  instead  of 
pullets'  eggs  for  hatching.  The  work  of  Pearl  (1909)  with  Plymouth 
Rocks  does  not  show  agreemsnt  with  this  theory. 

There  S33m  to  b3  no  gradual  and  consistent  changes  thruout  the  life 
of  the  bird  for  any  of  the  threo  egg  characters  studied.  Nearly  all  of  the 
changes  noted  occur  between  the  productions  of  the  first  and  the  second 
year.  Since  the  eggs  produced  during  the  second  year  are  nearer  to  the 
mean  for  the  entire  life  production  of  a  bird  kept  for  from  thres  to  four 
years,  it  would  b3  expected,  and  was  found  generally,  that  the  eggs 
selected  for  incubation  produced  by  hens  two  years  old  or  older,  gave 
more  consistent  correlations  than  those  produced  by  pullets. 

The  positive  relation  of  the  size  of  the  egg  incubated  to  the  size  of  the 
resultant  chick  and  mature  bird,  is  of  value  to  poultrymen  who  are  inter- 
ested in  the  production  of  either  poultry  or  eggs. 

The  inheritance  of  the  characters  studied  is  undoubtedly  of  the  type 
of  a  Galton  regression.  Much  further  study  is  needed  in  order  to  properly 
analyze  the  unit  factors,  or  physiological  units,  involved  in  the  formation 
of  the  broad  practical  characters  here  observed.  Until  further  results 
are  available,  however,  the  fact  that  certain  general  lines  of  inheritance 
ars  known  gives  breeders  some  evidence  on  which  to  base  more  work 
for  the  improvement  of  their  flocks. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  307 

SUMMARY 

The  most  important  results  obtained  from  the  studies  reported  in  this 
paper  may  be  grouped  into  the  following  conclusions: 

1.  The  variability  of  a  bird's  production  for  a  certain  character  does 
not  depend  on  the  difference  existing  between  that  bird's  parents  for  the 
same  character. 

2.  Both  the  male  and  the  female  have  a  distinct  and  approximately 
equal  effect  on  the  type  of  egg  produced  by  the  progeny,  but  the  combined 
effect  of  the  two  is  much  greater  and  is  directly  inherited  by  the  progeny, 
as  is  shown  by  the  type  of  egg  produced. 

3.  A  mating  of  two  opposite  extremes  of  character  always  caused  the 
production  of  a  medium  character  in  the  progeny. 

4.  A  mating  of  two  similar  extremes  of  character  usually  caused  the 
production  of  a  character  approaching  normal,  in  the  progeny. 

5.  It  appears  that  small  size  and  length  of  egg  are  dominant,  while 
there  seems  to  be  no  dominancy  whatever  for  color. 

6.  The  correlations  between  the  type  of  egg  incubated  and  the  mean 
type  produced  during  the  life  of  the  respective  progeny,  are  positive  in 
every  instance  and  are  significant  except  for  the  color  character.     These 
correlations  are  not  so  significant  as  those  between  the  mean  types  of 
eggs  produced  by  the  parents  and  the  respective  progeny. 

7.  The  color  character  is  much  more  irregular  than  the  size  or  the 
shape,  and  less  reliance  can  be  placed  on  the  stability  of  any  color  type 
when  selecting  eggs  for  hatching. 

8.  It  does  not  appear  that  any  more  reliance  can  be  placed  on  the 
stability  of  the  progeny  type  hatched  from  hens'  eggs  than  on  that  hatched 
from  pullets'   eggs. 

9.  The  type  of  egg  incubated  affects  the  mean  type  of  egg  produced 
during  the  life  of  the  bird  hatched,  to  a  greater  extent  than  it  affects 
the  pullet-year  production  or  the  production  of  any  other  single  year. 

10.  A  strong  correlation  exists  between  the  types  of  eggs  produced  by 
individuals  and  the  types  of  eggs  from  which  these  individuals  were 
hatched. 

11.  There  is  no  correlation  between  the  size  and  the  shape  of  eggs 
produced  by  the  birds  used  in  this  experiment. 

12.  The  size,  the  shape,  and  the  color  of  the  egg  seem  to  have  no  effect 
on  its  incubation  record. 


308  EARL  W.  BENJAMIN 

13.  No  definite  tendency  is  shown  toward  a  reduction  of  the  variability 
of  type  of  eggs  produced  by  individual  birds  during  successive  years. 

14.  During  the  pullet  year  the  size  of  the  eggs  produced  increases 
rapidly,  but  after  the  first  year's  production  no  appreciable  change  in 
the  size  of  the  eggs  produced  can  be  found. 

15.  There  seems  to  be  no  perceptible  and  consistent  difference  between 
the  shapes  of  eggs  laid  by  pullets  and  those  laid  by  hens. 

16.  There  is  a  tendency  for  the  eggs  produced  each  year,  even  in  the 
pullet  year,  to  have  a  gradually  increasing  index  until  the  fifth  or  the 
sixth  month  of  production,  after  which  this  index  gradually  decreases 
until  the  season's  production  ceases. 

17.  The  eggs  produced  by  hens  two  years  old  or  older,  are  more  likely 
to  be  tinted,  or  are  tinted  darker,  than  the  eggs  produced  by  the  same  birds 
during  their  pullet  year. 

18.  There  is  no  gradual  darkening  of  the  shell  pigment  after  the  second 
year's  production. 

19.  Each  year  there  is  a  tendency  for  the  eggs  produced  to  gradually 
become  whiter  during  the  first  five  or  six  months  of  production,  and  then 
to  become  more  tinted  again  toward  the  end  of  the  production  season. 

20.  The  data  presented  show  that  when  eggs  are  laid  by  an  individual 
bird  for  two  or  more  successive  days,  the  eggs  become  successively  smaller, 
have  a  larger  index,  and  are  more  deeply  tinted. 

21.  A  distinct  positive  correlation  is  found  between  the  size  of  the  eggs 
incubated  and  the  vigor  of  the  respective  chicks  hatched,   at  various 
ages  of  the  chicks.     The  correlation  is  especially  significant  during  the 
period  of  severe  weather  conditions. 

22.  A  constant  figure  to  represent  x  in  the  ratio,  female  weight :  male 
weight : :  x :  1,  was   calculated  for   a  part   of   the   available   material  at 
various   ages,  and  this  figure  was   found  to  agree  closely  with  Galton's 
constant  for  human  stature  of  0.93. 

23.  There  is  a  significant  positive  correlation  between  the  size  of  the 
eggs  incubated   and  the  size   of  the  respective   chicks   hatched.     This 
correlation  persists  during  the  life  of  the  birds  as  far  as  it  was  studied; 
that  is,  during  a  period  of  228  weeks. 

24.  All  of  the  eggs  produced  by  any  one  hen  tend  to  be  of  a  characteristic 
type  as  to  size,  shape,  and  color. 


STUDY  OF  SELECTIONS  FOR  SIZE,  SHAPE,  AND  COLOR  OF  HENS'  EGGS  309 

25.  Certain  individuals  have  the  power  to  transmit  their  characters 
much  better  than  do  others. 

26.  The  results  of  these  studies  indicate  a  condition  of  inheritance 
resembling  a  Galton  regression,  for  all  characters  studied. 

ACKNOWLEDGMENTS 

The  materials  and  equipment  used  for  this  study  were  supplied  by  the 
Department  of  Poultry  Husbandry  of  the  New  York  State  College  of 
Agriculture  at  Cornell  University.  The  writer  wishes  to  express  his 
appreciation  for  these  facilities  and  for  the  valuable  advice  furnished  by 
Professor  James  E.  Rice,  of  the  Department.  The  helpful  suggestions 
given  by  Dr.  H.  H.  Love,  of  the  Department  of  Plant  Breeding  at  Cornell 
University,  are  also  appreciated. 


310  EARL  W.  BENJAMIN 


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Memoir  29,  The  Lecithin  Content  of  Butter  and  its  Possible  Relationship  to  the  Fishy  Flavor,  the  second 
preceding  number  in  this  series  of  publications,  was  mailed  on  December  23,  1919. 


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